bluuebunny/crossref_metadata_2025 huggingface dataset:
Crosses between cultivars and tissue culture‐selected plants for salt resistance improvement in rice,Oryza sativa
Authors: Zhu G. Y. , Kinet J. ‐M. , Bertin P. , Bouharmont J. , Lutt S.
Published: March 2003

Several R2somaclonal families were derived from plants regenerated from a salt‐resistant callus of the salt‐sensitive rice cultivar ‘I Kong Pao’ (IKP). The family R2‐1‐23, in the presence of NaCl exhibited higher yield performances than the initial cultivar. This improvement in salinity resistance, however, was not transmitted to following generations; despite a higher number of spikelets per plant, family R3‐1‐23 did not perform better than the initial cultivar because of a very low seed set. This somaclonal family, its initial being the cultivar IKP, the breeding line IR31785 (extremely salt‐sensitive) and the cultivar ‘Aiwu’ (moderately salt‐resistant), were used as parents for production ofhybrids. Four crosses, IKP×R3‐1‐23, IR31785 ×R3‐1‐23, IR31785× IKP and IKP ×‘Aiwu’, were performed. Most of the F1hybrids cultivated in the absence of salt exhibited increased performances compared with the mid‐parent, suggesting an heterosis effect for yield‐related parameters. F2populations were screened for salinity resistance and a clear improvement for yield in stress conditions was recorded for populations derived from IK×R3‐1‐23, IR31785×R3‐1‐23 and IR31785×IKP, although the mean level of increase over the mid‐parent (RIMP) varied depending on the population, the presence or absence of stress, and the quantified parameters. The results are discussed in relation to the usefulness of in vitro selection for obtaining interesting somaclonal variants useful to be integrated in classical breeding programmes for salinity resistance in rice.
Genetic variation for pod wall proportion in Lupinus albus
Authors: Lagunes‐Espinoza L. C. , Huyghe C. , Papineau J.
Published: March 2003

The proportion of pod walls is considered as a potential selection criterion for seed yield in white lupin. It has a negative and highly significant phenotypic relationship with the seed yield and the genetic correlation between both traits is negative and high. The present study over 2 years (1996 and 1998) evaluated the genetic variation of proportion of pod walls in a set of 325 spring‐sown white lupin accessions originating from 17 different countries. Wide ranges of variation for this trait and other pod components were observed. This variation has a geographical distribution. Egyptian ecotypes had the lowest proportions of pod walls while the Greek and Italian ecotypes had the highest. The between‐country range of variation for the proportion of pod walls, was lower than the within‐country range (0.25‐0.31 and 0.21‐0.36, respectively) and the within‐country variance accounted for 51% of the total genetic variation. The broad‐sense heritabilities of pod wall proportion and proportion of pod walls for one full locule were moderate (0.44 and 0.57, respectively), which indicates that the proportion of pod walls can be used in breeding.
Effects of the two most common Wx alleles on different genetic backgrounds in rice
Authors: Mikami I. , Dung L.‐V. , Hirano H. ‐Y. , Sano Y.
Published: March 2003

Wxa and Wxb are the most common alleles of the Wx gene in Asian cultivated rice. The difference between them is responsible for differences in the levels of the Wx gene product in the endosperm, as well as in amylose content, which is an important determinant of the quality of edible rice. Since Indica rice mostly carries the Wxa allele, we introduced the Wxb allele into Indica‐type rice (IR36) from a Japonica‐type rice (T65) by repeated backcrossing. In the near‐isogenic line (IR36 Wxb), the level of the Wx gene product was reduced and, as expected, the level of amylose. However, IR36Wxb had a lower amylose content than the recurrent parent of T65 with the Wxb allele. The results suggest that the Indica (IR36) background might lower the amylose content more than the Japonica (T65) background when the Wx allele is the same. The possible importance of modifiers that regulate expression of the Wx gene is also discussed in relation to improvements in the grain quality of rice.
Variation in root penetration ability, osmotic adjustment and dehydration tolerance among accessions of rice adapted to rainfed lowland and upland ecosystems
Authors: Chandra Babu R. , Shashidhar H. E. , Lilley J. M. , Thanh N. D. , Ray J. D. , Sadasivam S. , Sarkarung S. , O'Toole J. C. , Nguyen H. T.
Published: March 2003

Drought is the major constraint limiting rainfed rice production. The ability of rice roots to penetrate compacted soils and therefore to increase water extraction capacity, osmotic adjustment and dehydration tolerance of leaves enables the plant to tolerate drought. Experiments were conducted to determine the extent of genetic variation in root penetration index, osmotic adjustment and dehydration tolerance among indica accessions adapted to rainfed lowlands as well as traditional varieties from rainfed uplands. Root penetration index was evaluated in a system using wax–petrolatum layers to simulate soil compaction. Osmotic adjustment and dehydration tolerance were studied under slow development of water stress. Substantial genetic variation was found for root penetration index, osmotic adjustment and dehydration tolerance among indica ecotypes from lowlands, and the study of several traditional varieties from uplands showed variation in root penetration index and related root traits. An indica accession, IR58821‐23‐B‐1‐2‐1 had a high root penetration index of 0.38. The accessions, IR61079‐33‐1‐2‐2‐3, IR62266‐42‐6‐2 and IR63919‐38‐B‐1 had high osmotic adjustment capacities (1.91, 1.90 and 1.78 MPa, respectively); IR61079‐33‐1‐2‐2‐3 also had high dehydration tolerance. Good osmotic adjustment and dehydration tolerance were associated with poor root system. The traditional varieties ‘Kallurundaikar’ and ‘Norungan’ had higher root penetration indices (0.46 and 0.43, respectively), than even the japonica accessions. The study identified indica accessions and traditional varieties with superior root‐ and shoot‐related drought resistance traits that could be used in breeding for drought resistance in rice.
Influence of genotype and culture medium on callus formation and plant regeneration from immature embryos of Triticum turgidum Desf. cultivars
Authors: González J. M. , Friero E. , Jouve N.
Published: March 2003

Twelve durum wheat cultivars were evaluated for their response to in vitro tissue culture. Zygotic immature embryos were used to induce callus formation using four different Murashige and Skoog‐based media. Each contained 9.05 μM 2,4‐dichlorophenoxy acetic acid but differed in their carbon source (sucrose or maltose) and the presence of NaCl (0 mM or 40 mM). The influence of both genotype and medium on the type and percentage of callus produced was observed. Calli were either compact and frequently embryogenic, or soft and watery. Percentages ranged from 54 to 100%, depending upon genotype and induction medium. All calli were then plated on a regeneration medium containing 20 g/l sucrose, 2.68 μM 1‐naphthaleneacetic acid and 2.22 μ 6‐benzylaminopurine. The regeneration of plantlets was higher from compact than from soft calli, with a strong dependence on genotype and type of induction medium used. MSm induction medium (30 g/l maltose) and MS40s (30 g/l sucrose plus 40 mM NaCl) were best for inducing compact calli, and gave the highest proportion of regenerated plants. The in vitro response (number of total shoots from a compact callus/number of embryos plated) was higher for immature embryos of ‘Baztan’, ‘Bradano’ and ‘Don Pedro’. These cultivars are a good starting material for experiments involving transformation of calli from zygotic immature embryos.
A cytogenetic study of bilateral sexual polyploidization in cassava (Manihot esculenta Crantz)
Authors: Ogburia M. N. , Yabuya T. , Adachi T.
Published: March 2003

Microsporogenesis and megasporogenesis were cytogenetically and histologically analysed in three cassava clones:‘Rayong 1′,‘Rayong 60′,‘M. mga’ and two hybrid lines,‘OMR 3641‐1’ and ‘OMR 3641‐1’ to elucidate the evolution of sexual polyploids in cassava. At telophase II, formation of 17‐21 micronuclei per pollen cell plate was observed in 16 out of 351 cell plates in ‘M. mga’. Micronuclei were observed at low (0.3‐2.3%) frequencies, at the sporad stage in all clones. Monads, dyads, triads and tetrads, which are established sources of high ploidy levels were observed at low (2.6%) and high (22.2%) frequencies. Megasporogenesis in ‘Rayong 1’ and ‘Rayong 60’ showed a lack of second meiotic divisions after a successful first division that resulted in partly unreduced embryo sacs with 2n eggs, suggesting another unrecognized and, as yet, unreported source of sexual polyploid formation in cassava. Meiotic abnormalities during microsporogenesis and megasporogenesis are implicated as being responsible for the formation of mixoploids (triploids and tetraploids) in cassava breeding programmes. A cytogenetic mechanism resulting in bilateral sexual polyploids through different gametic fertilization pathways in cassava is suggested and its role in breeding is briefly discussed.
RAPD‐based detection of genomic instability in soybean plants derived from somatic embryogenesis
Authors: Gesteira A. S. , Otoni W. C. , Barros E. G. , Moreira M. A.
Published: March 2003

Random amplified polymorphic DNA (RAPD) markers were used to evaluate genetic stability of regenerants of soybean plants obtained through somatic embryogenesis using 180 μM 2,4‐dichloro‐phenoxy acetic acid. Twenty primers were used to screen 44 regenerants from the cultivar ‘Spring’ and 28 from the cultivar ‘CAC‐1’. Three primers were polymorphic for two of the ‘Spring’‐derived regenerants, with a somaclonal frequency of 4.5%. Four primers were polymorphic for the ‘CAC’‐l‐derived regenerant, with a somaclonal frequency of 3.57%. The results indicate the usefulness of RAPD markers to detect genetic instability in soybean primary regenerant plants derived from somatic embryogenesis, and as a certification tool for monitoring genetic stability during the regeneration process.
Inheritance of reduced linolenic acid content in the Ethiopian mustard mutant N2‐4961
Authors: Velasco L. , Fernández‐Martínez J. M. , Haro A. De
Published: March 2003

The zero erucic acid Ethiopian mustard lines developed so far are characterized by an exceptionally high linolenic acid content in the seed oil. The mutant line N2‐4961, expressing low linolenic acid content in a high erucic acid background, was developed through chemical mutagenesis. The objective of this research was to study the inheritance of low linolenic acid content in this mutant. Line N2‐4961 was reciprocally crossed with its parent line C‐101 and the linolenic acid content of the reciprocal F1, F2 and BC1 generations was studied. No maternal, cytoplasmic or dominance effects were detected in the analysis of F1 seeds and F1 plants from reciprocal crosses. Linolenic acid content segregated in 1: 2: 1 ratios in all the F2 populations studied, suggesting monogenic inheritance. This was confirmed with the analysis of the reciprocal backcross generation. The simple inheritance of low linolenic acid content in N2‐4961 will facilitate the transference of this trait to zero erucic acid lines of Ethiopian mustard.
Genetic analysis of total glucosinolate in crosses involving a high glucosinolate Indian variety and a low glucosinolate line of Brassica juncea
Authors: Sodhi Y. S. , Mukhopadhyay A. , Arumugam N. , Verma J. K. , Gupta V. , Pental D. , Pradhan A. K.
Published: March 2003

Analysis of the glucosinolate content and composition by high‐pressure liquid chromatography indicated that varieties of Brassica juncea bred and grown in India have a high glucosinolate content characterized by the presence of 2‐propenyl (allyl) and 3‐butenyl as the major and 4‐pentenyl as the minor fractions. In contrast, the B. juncea germplasm from other countries is characterized by the presence of 2‐propenyl as the major glucosinolate fraction, trace amounts of 3‐butenyl and a total lack of the 4‐pentenyl types. In order to transfer the low glucosinolate trait to Indian B. juncea, the inheritance of total glucosinolates was investigated using doubled haploid (DH) populations derived from F1 (DH1) and BC1 (BC1DH) of a cross between ‘Varuna’ (the most widely cultivated high glucosinolate variety of India) and ‘Heera’ (a non‐allyl type low glucosinolate line). A total of 752 DH1 and 1263 BC1DH gave rise to seven and 11 low glucosinolate (containing less than 18 μmol/g seed) individuals, respectively. On the basis of the frequency of the low glucosinolate individuals, the total glucosinolate was found to be under the control of seven genes. There was presence of both allyl and non‐allyl types in DH1 and BC1DH low‐glucosinolate individuals and absence of 3‐butenyl glucosinolate in some of the BC1DH low glucosinolate individuals, indicating segregation for these fractions in the population. The size of the segregating DH population proved to be crucial for precise determination of the number of genes controlling the trait. Because of the large number of genes involved, incorporation of low glucosinolate trait in Indian B. juncea should be approached through doubled haploid (DH) breeding.
Microsatellite marker for yellow rust resistance gene Yr5 in wheat introgressed from spelt wheat
Authors: Sun Q. , Wei Y. , Ni Z. , Xie C. , Yang T.
Published: March 2003

Yellow rust of wheat caused by Puccinia striiformis f sp. tritici has been periodically epidemic and severely damaged wheat production in China and throughout the world. Breeding for resistant cultivars has been proved to be an effective way to resolve the problem. A yellow rust resistance gene, Yr5, derived from Triticum spelta shows immunity or high resistance to the most popular isolates Tiaozhong 30 and 31 in China. Establishment of DNA markers for the Yr5 gene will facilitate marker‐assisted selection and gene pyramiding in the breeding programme. Since the Yr5 gene was cytologically located on the long arm of chromosome 2B, By33, the donor of Yr5, was crossed and backcrossed with the susceptible line 441, and BC3F2 and BC3F3 segregating populations were screened for polymorphism by using 11 microsatellite primers mapped on chromosome 2B. A marker, Xgwm501‐195 bp/160 bp, was found to be linked to Yr5, with a genetic distance of 10.5‐13.3 cM.
Waxy proteins in diploid, tetraploid and hexaploid wheats
Authors: Urbano M. , Margiotta B. , Colaprico G. , Lafiandra D.
Published: March 2003

Electrophoretic analyses of waxy proteins, encoded by genes present at the Wx‐1 loci, present in several cultivars and accessions of hexaploid wheat, Triticum aestivum, have permitted the detection of null alleles at the Wx‐B1 and Wx‐D1 loci. Polymorphism at the Wx‐A1 and Wx‐B1 loci was also investigated in several accessions of tetraploid wheats, Triticum durum, Triticum dicoccoides and Triticum timopheevi, and in diploid species, Triticum urartu, Triticum boeoticum and Triticum monococcum. One null allele at the Wx‐A1 locus and three polymorphic alleles at Wx‐B1 locus were detected in T. durum; a new allele at one of the two waxy loci was identified in the tetraploid wheat T. timopheevi; no polymorphism was detected in diploid species. Polymerase chain reaction techniques made possible the detection of further polymorphism existing at the Wx‐1 loci and the reason for the lack of expression of the null genotypes to be investigated. The null forms detected at each locus have been used to produce complete sets of partial and total waxy lines in durum and bread wheat.
Molecular and physical mapping of genes affecting awning in wheat
Authors: Sourdille P. , Cadalen T. , Gay G. , Gill B. , Bernard M.
Published: March 2003

Quantitative trait loci (QTL) for three traits related to awning (awn length at the base, the middle and the top of the ear) in wheat were mapped in a doubled‐haploid line (DH) population derived from the cross between the cultivars ‘Courtot’ (awned) and ‘Chinese Spring’ (awnless) and grown in Clermont‐Ferrand, France, under natural field conditions. A molecular marker linkage map of this cross that was previously constructed based on 187 DH lines and 550 markers was used for the QTL mapping. The genome was well covered (more than 95%) and a set of anchor loci regularly spaced (one marker every 20.8 cM) was chosen for marker regression analysis. For each trait, only two consistent QTL were identified with individual effects ranging from 8.5 to 45.9% of the total phenotypic variation. These two QTL cosegregated with the genes Hd on chromosome 4A and B2 on chromosome 6B, which are known to inhibit awning. The results were confirmed using ‘Chinese Spring’ deletion lines of these two chromosomes, which have awned spikes, while ‘Chinese Spring’ is usually awnless. No quantitative trait locus was detected on chromosome 5A where the B1 awn‐inhibitor gene is located, suggesting that both ‘Courtot’ and ‘Chinese Spring’ have the same allelic constitution at this locus. The occurrence of awned speltoid spikes on the deletion lines of this chromosome suggests that ‘Chinese Spring’ and ‘Courtot’ have the dominant B1 allele, indicating that B1 alone has insufficient effect to induce complete awn inhibition.
Chromosome doubling of haploid maize seedlings using nitrous oxide gas at the flower primordial stage
Authors: Kato A. , Geiger H. H.
Published: March 2003

In maize, inbred lines are used for the production of hybrid varieties. Corn breeders and researchers have considered using haploids to develop inbred lines; however, this procedure has not been practically applied because of the inefficiency of chromosome doubling of maize haploid seedlings. In this report, a procedure has been developed to overcome this difficulty. Maize haploid seedlings obtained from eight different genotypes were treated with nitrous oxide gas (2 days at 600 kPa). Treatment at the six‐leaf stage (flower primordia formation stage) significantly increased the occurrence of fertile sectors on both tassels and ears so that approximately half (44%) of the treated haploids produced kernels after self‐pollination. In the control, only 11% of haploids produced selfed kernels owing to spontaneous chromosome doubling. A strong genotypic effect on the occurrence of fertile sectors after the treatment was observed. This procedure can be used for inbred line development in maize breeding programmes.
Development of self‐incompatibleBrassica napus:(I) introgression of S‐alleles fromBrassica oleraceathrough interspecific hybridization
Authors: RIPLEY V. L. , BEVERSDORF W. D.
Published: March 2003

Cultivars inBrassica napusvar.oleifera, a self‐pollinating, self‐compatible species, have traditionally been developed as open‐pollinated lines or populations. Significant yield gains in this species have been realized through the exploitation of heterosis. Commercial hybrid production has been possible as a result of the development of a number of pollination control systems. Self‐incompatibility was transferred fromB. oleraceavar.italicatoB. napusvar.oleiferathrough interspecific hybridization. The response to interspecific pollination, as measured by pod elongation and initial stages of ovule development, was genotype dependent, and two highly responsiveB. napusgenotypes were identified. Embryo rescue was used to produce the interspecific hybrids. Isoelectric focusing of stigma proteins was used to identify S‐alleles in the interspecific hybrids to facilitate backcrossing. Segregation of the S‐locus through a series of back‐crosses toB. napuswas complicated by aneuploidy; however, the S‐locus was found to segregate as a single gene. Usefulness ofB. oleraceaas a source of S‐alleles for pollination control inB. napusis discussed.
Functional Sperm Parameters and Fertility of Bull Semen Extended in Biociphos‐Plus® and Triladyl®
Authors: Gil J , Januskauskas A , Håård MCh , Håård Mgm , Johanisson A , Söderquist L , Rodriguez‐Mártinez H
Published: March 2003

Contents

Twenty ejaculates from five dairy AI‐bulls were used to compare, in a split‐sample experiment, the fertility [56 day‐non‐return‐rate (NRR) from more than 14000 AI) and sperm viability post‐thaw of semen diluted with an egg yolk‐ (Triladyl®) or soybean‐based (Biociphos‐Plus®) commercial extender. The in vitro evaluations were divided in two experiments. Experiment 1 (n = 20) included post‐thaw evaluations of motility (subjective and computerized), membrane integrity (CalceinAM/EthD‐1, SYBR‐14/PI, and osmotic resistance test; ORT), and capacitation status (CTC/EthD‐1). Experiment 2 (n = 10) included evaluations of the capacitation‐(CTC/EthD‐1) and acrosome status (FITC‐PSA/EthD‐1) during incubation with/without a challenge with solubilized zona pellucida proteins (SZP). No significant difference in the fertility (69.1 ± 0.8 versus 69.2 ± 0.8) results was found between the two extenders. In experiment 1, the computerized motility evaluations post‐thaw (CASA) showed higher values for Biociphos‐Plus® processed semen for the velocity patterns and lateral sperm head displacement. After 6 h at room temperature (20–22°C) all the CASA motility patterns were significantly higher for Biociphos‐Plus®. The proportion of spermatozoa with intact membranes assessed by CalceinAM was significantly higher in Biociphos‐Plus® (p < 0.001) compared to Triladyl®, but such difference was not seen when using SYBR‐14 or the ORT‐assay. When using the CTC/EthD‐1 assay, a lower proportion of acrosome reacted (AR) spermatozoa post‐thaw (p < 0.01) was found in Biociphos‐Plus® processed semen, as well as a tendency (p < 0.07) for a higher number of uncapacitated spermatozoa. In experiment 2, the proportion of uncapacitated spermatozoa was significantly higher for Biociphos‐Plus® when semen was incubated (38°C and 5% CO2) without SZP at both 0 (p < 0.001) and 30 min (p < 0.05). Concomitantly, Triladyl® showed a higher percentage of capacitated spermatozoa at 0 (p < 0.01), 30 (p < 0.05) and 120 min (p < 0.05). A higher (p < 0.05) incidence of AR‐spermatozoa was seen in Triladyl® at the beginning of the incubation with SZP. No significant difference between extenders was detected for the acrosome status by the FITC‐PSA‐assay. Incubation with SZP induced acrosome reaction of capacitated spermatozoa in both extenders, which was detected by CTC and FITC‐PSA assays. In conclusion, fertility was not affected by Biociphos‐Plus® when 15 × 106 of spermatozoa per AI dose were inseminated. The finding that higher frequencies of spermatozoa seemed more membrane stable post‐thaw, when frozen in Biociphos‐Plus®, might indicate that this extender better protects the sperm viability compared with Triladyl®.
Interactions of Bovine Viral Diarrhoea Virus and Foot‐and‐mouth Disease Virus with Bovine Reproductive Tissues and Embryos
Authors: Vanroose G
Published: March 2003

ContentsThis review will focus upon the interactions of two important viral pathogens in cattle, bovine viral diarrhoea virus (BVDV) and foot‐and‐mouth disease virus (FMDV), respectively, with bovine reproductive tissues and embryos. Both viruses are widely spread throughout the world and cause serious economic losses due to death, loss of appetite and weight, respiratory disease, reproductive problems (infertility, early embryonic death, abortions) and decreased milk production (Baker, J Am Vet Med Assoc 190, 1449–1458, 1987; Kitching, J Comp Path 118, 89–108, 1998).
Colour‐coded and Pulsed Doppler Sonography of the Canine Testis, Epididymis and Prostate Gland: Physiological and Pathological Findings
Authors: Günzel‐Apel A‐R , Möhrke C , Nautrup C Poulsen
Published: March 2003

Two‐dimensional ultrasound was used in combination with colour‐coded and pulsed Doppler sonography to study the blood flow of the testes and prostate gland in a total of 30 male dogs. After detection of the vessels by colour‐coded Doppler sonography, the blood flow patterns were determined by pulsed Doppler sonography measuring and describing the systolic and diastolic peak velocity (SPV, DPV), the end‐diastolic velocity, the time‐averaged maximum velocity (TAMAX), the pulsatility and resistance index, as well as the ratios of the systolic peak velocity and end‐diastolic velocity and of the systolic and diastolic peak velocities. The blood flow of the testicular artery was measured within the pampiniform plexus and the marginal location. The prostatic blood supply was measured in the artery of the deferential duct (cranial), the prostatic artery outside (lateral) and within the gland (subcapsular). The physiological testicular flow pattern was monophasic with a high diastolic flow. Testes with neoplastic alterations showed a significant increase of SPV and TAMAX. The epididymal vessels could not be detected. Under physiological conditions the prostatic blood flow pattern was biphasic in the cranial and lateral location and monophasic in the subcapsular location. Benign prostatic hyperplasia was characterized by a significant increase of SPV, DPV and TAMAX. The results of the present investigation demonstrate that the colour‐coded and pulsed Doppler sonography give additional valuable information which improves the andrological diagnostics in the dog.
Modulation of Ovarian Function in Female Dogs Immunized with Bovine Luteinizing Hormone Receptor
Authors: Saxena BB , Clavio A , Singh M , Rathnam P , Bukharovich Y , Reimers T , Saxena A , Perkins Scott
Published: March 2003

Adult female dogs were immunized with 0.5 mg bovine luteinizing hormone receptor (LH‐R) encapsulated in a silastic subdermal implant and subsequently with four intramuscular booster injections of 0.1 mg LH‐R each. Circulating LH‐R antibody was detected in the sera 3 weeks post‐implant. The appearance of LH‐R antibody was associated with a decline in the serum progesterone concentrations to a range of 0–0.5 ng/ml until day 365 in the immunized dogs in comparison with a range of 5–10 ng in the control animals, suggesting a lack of ovulation and corpus luteum function in immunized dogs. The immunized dogs did not show signs of `standing heat' and failed to ovulate when induced by LH‐RH challenge. Serum oestradiol levels, however, remained in the range of 30–40 pg/ml in both the immunized and the control dogs. With the decline in the antibody titres, the hormonal profile and vaginal cytology returned to a fertile state and the dogs exhibited signs of `standing heat', as well as vaginal bleeding. Dogs immunized with LH‐R did not show any serious metabolic, local or systemic adverse effects. The hypothalamic–pituitary gonadal axis remained intact as indicated by little difference in pituitary LH levels between control and immunized animals, and by the release of LH by LH‐RH challenge. These studies demonstrate that active immunization of female dogs with LH‐R could immunomodulate ovarian function to cause a reversible state of infertility. It may be postulated that, due to extensive interspecies homology, a recombinant LH receptor‐based immunocontraceptive vaccine may also be effective in other vertebrates.
Comparative Analysis of Protein Synthesis, Transcription and Cytoplasmic Polyadenylation of mRNA during Maturation of Bovine Oocytes in vitro
Authors: Tomek W , Torner H , Kanitz W
Published: March 2003

Contents

In many species, large numbers of macromolecules are accumulated during oocyte growth. The messenger and ribosomal RNAs produced in these cells are far in excess of those necessary to support protein synthesis. Thus, the aim of this study was to elucidate the processes of translational regulation during meiotic maturation. The relationship between transcription, translation and polyadenylation of mRNA during in‐vitro maturation (IVM) of bovine oocytes was investigated. The results presented here show that overall protein synthesis is stimulated during meiotic maturation (approximately three times) concomitantly with the onset of germinal vesicle breakdown after 6 to 10 h of IVM. However, in metaphase II, the incorporation of [35S]methionine into proteins showed only basal levels, as in the germinal vesicle (GV) stage. Furthermore, in the course of IVM, de‐novo transcription strongly declines as determined by measuring the incorporation of [3H]uridine into RNA. In contrast to this finding, the incorporation of [3H]adenosine increased and showed a peak during the time interval from 6 to 10 h of IVM, parallel with the onset of germinal vesicle breakdown (GVBD) and translation. In the further course of maturation, only a moderate decrease of [3H]adenosine incorporation was observed. These results indicate that (i) translation increased at the time of GVBD; (ii) these processes were accompanied by polyadenylation of mRNA; and (iii) although transcription declines, polyadenylated mRNA is accumulated until metaphase II (as shown by poly(U)‐hybridization), in which protein synthesis is low. The correlation of these processes is discussed here. A detailed knowledge of the biochemical and molecular processes which occur during oocyte maturation can be useful for the improvement of IVM conditions.
Assessment of Suitable Porcine Semen for Freezing, According to the Ejaculate Characteristics in the Iberico × Landrace Breed
Authors: Gosálvez LF , Valdelvira JJ , Vidal A , Alvariño JMR
Published: March 2003

Contents

A total of 35 ejaculates were studied in order to assess the suitability of porcine semen for freezing according to the ejaculate characteristics. The effects of the freezing procedure were identified; a decrease in motility and acrosome quality was found after thawing. The best results on motility were linked to the ejaculates with a volume of less than 100 ml of the sperm‐rich fraction, a concentration lower than 450 × 106 spermatozoa/ml and an agglutination score below 2. However, the best normal apical ridge (NAR) was found when the volume of the sperm‐rich fraction was greater than 150 ml. For this reason, an intermediate volume of the sperm‐rich fraction of the ejaculate for the best motility and the best NAR, a concentration lower than 450 × 106 spermatozoa/ml and a rate of agglutination below 2 should provide the best quality after freezing. This study also attempted to determine whether a positive effect of ejaculate selection on the overall freezing performance might be expected.
Cell‐specific Distribution of Progesterone Receptors in the Bovine Ovary
Authors: Van den Broeck W , D'haeseleer M , Coryn M , Simoens P
Published: March 2003

Contents

This study describes the localization of progesterone receptors (PR) in the bovine ovary. Ovaries were obtained from 11 non‐pregnant and two pregnant cows. Progesterone receptors were visualized by immunohistochemistry on paraffin sections. Nuclear staining for PR was observed in cells of the follicles, corpora lutea, theca layers, surface epithelium, tunica albuginea, and in superficial and deep stroma cells. No staining was noticed in apoptotic bodies of atretic follicles. Expression of PR in follicle cells indicates an intrafollicular role of progesterone. The higher expression in thecal cells compared with follicle cells indicates that thecal cells mediate some effects of progesterone on the follicular development. Superficial stroma cells showing high expression might have a similar influence on primordial and primary follicles. In general, luteal cells had a lower expression than follicle cells, which may be explained by the down‐regulatory effect of locally produced progesterone. The lower expression in luteal cells during pregnancy can be due to the longer life span of this corpus luteum and concomitant degeneration of its PR. The high and rather constant expression of PR in cells of the surface epithelium remains to be elucidated.
Improving the Reproductive Efficiency, Pregnancy Diagnosis and Monitoring the Resumption of Luteal Activity in Indigenous Damascus Goats
Authors: Al‐Merestani MR , Zarkawi M , Wardeh MF
Published: March 2003

Contents

Seventy‐five female Damascus goats aged between 1.5 and 5.5 years were used to evaluate the effectiveness of the intravaginal sponges and prostaglandin analogue on oestrous synchronization and fecundity; to diagnose pregnancy and to monitor the resumption of the luteal activity. Females were divided randomly, during the breeding season, into three equal groups, S, P and C. Females in group S were fitted with sponges containing 45 mg of flugestone acetate (FGA) for 14 days and injected with pregnant mare serum gonadotrophin (PMSG) at the sponge withdrawal. Females in group P were given two injections of prostaglandin F2α analogue at 11‐day intervals, whereas females in group C (control) received no treatment. The results showed that there was a significant difference (p < 0.001) in oestrous exhibition between females in group S as compared with those in groups P and C, with means being 30 ± 10, 172 ± 115 and 217 ± 75 h for groups S, P and C, respectively. Kidding rates resulting from the first and all matings were 80 and 88, 52 and 88, and 68 and 80% for groups S, P and C, respectively. Fecundity rates were 215, 175 and 180% for groups S, P and C, respectively, with a significant difference (p < 0.05) between the S and both P and C groups. Using an ultrasound pregnancy detector performed on days 57 ± 3 after mating, positive pregnancy diagnosis was 93.3% and 100% for non‐pregnancy. Females in the control group showed functional corpus luteum starting in September. It is concluded that FGA sponges plus PMSG treatment could be successfully used to synchronize oestrus and improve fecundity; whereas prostaglandin treatment was not effective to synchronize oestrus. It is also concluded that pregnancy can be diagnosed accurately and successfully using an ultrasound pregnancy detector. In addition, ovarian activity in the Damascus goat in Syria resumes in September.
Quality improvement projects: Finding a pathway through policies
Authors: Cleary Michelle , Horsfall Jan
Published: March 2003

ABSTRACT:

It is increasingly common for mental health nurses to develop and implement quality improvement and/or research projects. The requirement that these activities be conducted in accordance with local, state and national policy; organizational accreditation frameworks; and within ethical frameworks is daunting. This paper aims to define relevant terms, relate some of the competing demands to each other and outline a pathway for developing nurse‐based quality‐related projects. When a specific exemplar is required, protocols from Central Sydney Area Mental Health Service will be drawn upon as it is likely that policy developed in this health area will not be significantly different to that of other health areas in New South Wales and other Australian States.
Bcl‐2 genes and growth factors in the pathology of ischaemic acute renal failure
Authors: Gobé G , Zhang X‐J , Cuttle L , Pat B , Willgoss D , Hancock J , Barnard R , Endre Z
Published: March 2003

For the past decade, an attempt has been made by many research groups to define the roles of the growing number of Bcl‐2 gene family proteins in the apoptotic process. The Bcl‐2 family consists of pro‐apoptotic (or cell death) and anti‐apoptotic (or cell survival) genes and it is the balance in expression between these gene lineages that may determine the death or survival of a cell. The majority of studies have analysed the role/s of the Bcl‐2 genes in cancer development. Equally important is their role in normal tissue development, homeostasis and non‐cancer disease states. Bcl‐2 is crucial for normal development in the kidney, with a deficiency in Bcl‐2 producing such malformation that renal failure and death result. As a corollary, its role in renal disease states in the adult has been sought. Ischaemia is one of the most common causes of both acute and chronic renal failure. The section of the kidney that is most susceptible to ischaemic damage is the outer zone of the outer medulla. Within this zone the proximal tubules are most sensitive and often die by necrosis or desquamate. In the distal nephron, apoptosis is the more common form of cell death. Recent results from our laboratory have indicated that ischaemia‐induced acute renal failure is associated with up‐regulation of two anti‐apoptotic Bcl‐2 proteins (Bcl‐2 and Bcl‐XL) in the damaged distal tubule and occasional up‐regulation of Bax in the proximal tubule. The distal tubule is a known reservoir for several growth factors important to renal growth and repair, such as insulin‐like growth factor‐1 (IGF‐1) and epidermal growth factor (EGF). One of the likely possibilities for the anti‐cell death action of the Bcl‐2 genes is that the protected distal cells may be able to produce growth factors that have a further reparative or protective role via an autocrine mechanism in the distal segment and a paracrine mechanism in the proximal cells. Both EGF and IGF‐1 are also up‐regulated in the surviving distal tubules and are detected in the surviving proximal tubules, where these growth factors are not usually synthesized. As a result, we have been using in vitro methods to test: (i) the relative sensitivities of renal distal and proximal epithelial cell populations to injury caused by mechanisms known to act in ischaemia–reperfusion; (ii) whether a Bcl‐2 anti‐apoptotic mechanism acts in these cells; and (iii) whether an autocrine and/or paracrine growth factor mechanism is initiated. The following review discusses the background to these studies as well as some of our preliminary results.
Preproenkephalin is a Th2 cytokine but is not required for Th2 differentiation in vitro
Authors: Hook S , Camberis M , Prout M , Konig M , Zimmer A , Van Heeke G , Le Gros G
Published: March 2003

Preproenkephalin (PPNK) mRNA expression has been detected in many cells of the immune system, including monocytes and lymphocytes. In the present paper, the expression of PPNK mRNA in purified CD4+ Th1 and Th2 lymphocyte subpopulations is investigated and correlated with the presence of the opioid neuropeptides leu‐ and met‐enkephalin. We found that PPNK mRNA and met‐enkephalin were present at higher levels in the Th2 cultures compared with the Th1 cultures. Lymphocytes from PPNK‐deficient mice were then used to look at the role of PPNK in Th2 lymphocyte differentiation. Lymphocytes from these mice could be driven into a Th2 phenotype, suggesting that cultures containing IL‐4 do not require PPNK for Th2 differentiation.
Expression of interleukin‐1 receptors in the later period of foetal thymic organ culture and during suspension culture of thymocytes from aged mice
Authors: Oh Soon‐Hwan , Kim Kilhyoun
Published: March 2003

Interleukin‐1 has been reported to be involved in thymocyte development by exerting a variety of effects on immature CD4–CD8– double‐negative (DN) thymocytes. In contrast to the well‐documented involvement of IL‐1 in thymocyte development, expression of IL‐1 receptors (IL‐1R) on thymocytes has not been well demonstrated. In the present study, expression of IL‐1R on the developing thymocytes was investigated. Although normal thymocytes barely express IL‐1R, expression of IL‐1R (type I) substantially increased at days 12–15 of foetal thymic organ culture (FTOC), with an increase of the DN subset. The CD4/CD8 profile of the IL‐1R (type I)+ cells showed that these cells were mostly restricted to the DN and CD4+CD8+ subsets. Interestingly, in vitro culture of the thymocytes from an aged mouse, but not those from young adult or newborn mice, revealed similar results to those of FTOC. In addition, half of the IL‐1R+ cells that increased in the later period of FTOC were γδ thymocytes. These results demonstrate IL‐1R expression on thymocytes during ex vivo culture and suggest that IL‐1R is expressed in a certain environment during normal thymocyte differentiation.
Fluorescent dyes for lymphocyte migration and proliferation studies
Authors: Parish Christopher R
Published: March 2003

Fluorescent dyes are increasingly being exploited to track lymphocyte migration and proliferation. The present paper reviews the properties and performance of some 14 different fluorescent dyes that have been used during the last 20 years to monitor lymphocyte migration. Of the 14 dyes discussed, two stand out as being the most versatile in terms of long‐term tracking of lymphocytes and their ability to quantify lymphocyte proliferation. They are the intracellular covalent coupling dye carboxyfluorescein diacetate succinimidyl ester (CFSE) and the membrane inserting dye PKH26. Both dyes have the advantage that they can be used to track cell division, bothin vitroandin vivo, due to the progressive halving of the fluorescence intensity of the dyes in cells after each division. However, CFSE appears to have the edge over PKH26 based on homogeneity of lymphocyte staining and cost. Two other fluorescent dyes, although not suitable for lymphocyte proliferation studies, are valuable tracking dyes for short‐term (up to 3 day) lymphocyte migration experiments, namely the DNA‐binding dye Hoechst 33342 and the cytoplasmic dye calcein. In the future it is highly likely that additional fluorescent dyes, with different spectral properties to CFSE, will become available, as well as membrane inserting fluorescent dyes that more homogeneously label lymphocytes than PKH26.
The anti‐idiotypic antibody 1F7 selectively inhibits cytotoxic T cells activated in HIV‐1 infection
Authors: Grant Michael , Smaill Fiona , Muller Sybille , Kohler Heinz , Rosenthal Kenneth
Published: March 2003

Circulating CD8+ T lymphocyte numbers rise substantially following infection with HIV‐1. This expanded CD8+ T cell population includes HIV‐specific CTL and CTL that kill activated uninfected CD4+ lymphocytes. Experimental, epidemiological and clinical evidence supports the possibility that expansion of CD8+ CTL contributes to CD4+ T cell depletion and disease progression in human HIV infection. Therefore, modulation of CD8+ T cell numbers or of certain CD8+ CTL activated in HIV‐infected individuals may be beneficial. It was found that 1F7, a mAb against an idiotype common to anti‐HIV and anti‐simian immunodeficiency virus (SIV) antibodies, selectively inhibited both anti‐HIV CTL and CTL against uninfected CD4+ T cells. Alloantigen‐specific CTL and NK cells from either HIV‐infected individuals or controls were unaffected by 1F7. Prolonged incubation of CD8+ T cells from HIV‐infected individuals with 1F7 induces apoptosis, which was shown to be reflected functionally in reduced total CTL activity and in especially reduced CTL activity against uninfected CD4+ lymphocytes. The selective reactivity of 1F7 with certain CD8+ CTL could be applied towards the modulation of CD8+ T cell responses involved in AIDS pathogenesis.
Dendritic cells: Multiple subtypes, multiple origins, multiple functions
Authors: Shortman Ken
Published: March 2003

The dendritic cells (DC) of the mouse are surprisingly heterogeneous by surface phenotype and may be segregated based on expression of CD4 and CD8. These DC subtypes appear to differ in developmental origin and display some differences in biological function, including regulation of the cytokine production of the T cells that they activate. This presentation reviews the attempts of one laboratory to understand this complex DC system.
Analysis of the functional characteristics of L‐selectin and its expression on normal and CD18‐deficient bovine neutrophils
Authors: Nagahata H , Higuchi H , Yamashiki N , Yamaguchi M
Published: March 2003

In vivoresponsiveness to epinephrine, expression of L‐selectin on neutrophils, changes in intracellular calcium ([Ca2+]i), sulfatide‐induced superoxide production and tyrosine phosphorylation in neutrophils were evaluated to elucidate the role of L‐selectin‐associated functions of normal and CD18‐deficient bovine neutrophils. The number of neutrophils in peripheral blood was significantly increased (P< 0.05) in four normal calves at 5–20 min afterin vivoadministration of epinephrine; however, no significant increase of neutrophils was found in three calves with bovine leucocyte adhesion deficiency (BLAD). Expression of L‐selectin on neutrophils from three calves with BLAD was 61–77% of that of normal calves. Pretreatment of neutrophils with phorbol myristate acetate caused a marked decrease in the expression of L‐selectin on neutrophils from both normal and BLAD calves. The sulfatide‐induced sustained phase of [Ca2+]iconcentration in neutrophils from calves with BLAD was significantly (P< 0.05) decreased. Following stimulation with aggregated IgG, the transient phase of [Ca2+]iin neutrophils from normal and BLAD calves was increased; however, the sustained phase of [Ca2+]iin BLAD neutrophils was significantly lower (P< 0.05) than that of controls. Sulfatide‐induced O2−production and chemiluminescent response in neutrophils from calves with BLAD were 48–51% of those of normal calves and were inhibited by genistein and wortmannin, respectively, in a dose‐dependent manner. The amount of tyrosine phosphorylated 100 kDa protein in neutrophils from BLAD calves stimulated with sulfatides was 57% of that of controls. The degree of L‐selectin expression on neutrophils was correlated with the intracellular signalling events and the related superoxide production.
Neurotransmitter release at ribbon synapses in the retina
Authors: Morgans Catherine W
Published: March 2003

The synapses of photoreceptors and bipolar cells in the retina are easily identified ultrastructurally by the presence of synaptic ribbons, electron‐dense bars perpendicular to the plasma membrane at the active zones, extending about 0.5 μm into the cytoplasm. The neurotransmitter, glutamate, is released continuously (tonically) from these ‘ribbon synapses’ and the rate of release is modulated in response to graded changes in the membrane potential. This contrasts with action potential‐driven bursts of release at conventional synapses. Similar to other synapses, neurotransmitter is released at ribbon synapses by the calcium‐dependent exocytosis of synaptic vesicles. Most components of the molecular machinery governing transmitter release are conserved between ribbon and conventional synapses, but a few differences have been identified that may be important determinants of tonic transmitter release. For example, the presynaptic calcium channels of bipolar cells and photoreceptors are different from those elsewhere in the brain. Differences have also been found in the proteins involved in synaptic vesicle recruitment to the active zone and in synaptic vesicle fusion. These differences and others are discussed in terms of their implications for neurotransmitter release from photoreceptors and bipolar cells in the retina.
Cross‐reactivity in T‐cell antigen recognition
Authors: Regner Matthias
Published: March 2003

The molecular interactions between the T‐cell receptor (TCR) and peptide‐MHC (pMHC) have been elucidated in recent years. Nevertheless, the fact that binding of only slightly different ligands by a TCR, or ligation of the same pMHC at different developmental stages of the T cell, can have opposing consequences, continues to pose intellectual challenges. Kinetic proofreading models, which have at their core the dissociation rates of pMHC from the TCR, are best suited to account for these observations. However, T cells can be triggered by peptides with often minimal homology to the primary immunogenic peptide. This cross‐reactivity of the TCR is manifest at several levels, from positive selection of immature thymocytes to homeostasis and antigen‐cross‐ reactive immune responses of mature peripheral T cells. The implications of the high cross‐reactivity of T‐cell antigen recognition for self‐tolerance and T‐cell memory are discussed.