bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequence analysis of 0.4 megabases of the rabbit germline immunoglobulin kappa1 light chain locus
Authors: Ros F. , Reichenberger N. , Dragicevic T. , Van Schooten W. C. A. , Buelow R. , Platzer J. 
Published: January 2005

SummaryTwo rabbit germline bacterial artificial chromosome (BAC) libraries from animals with the b5 and b4 allotype were screened with probes specific for the immunoglobulin kappa1 light chain locus. Two partially overlapping BAC clones containing Vκ elements of b5 allotype were isolated from the b5 library and one BAC clone containing Jκ1, Cκ and Vκ was isolated from the b4 library. These three BAC clones were sequenced. They span about 0.4 MB of the rabbit Ig κ1 light chain locus including 36 Vκ elements, five J elements and the coding region of Cκ1. The organization of the locus and the potential function of newly identified functional and structural elements are discussed.
Effects of polymorphic microsatellites in the regulatory region of IGF1 and GHR on growth and carcass traits in beef cattle
Authors: Curi R. A. , de Oliveira H. N. , Silveira A. C. , Lopes C. R. 
Published: January 2005

SummaryGrowth hormone (GH), insulin‐like growth factors 1 and 2 (IGF1 and IGF2) and their associated binding proteins and transmembrane receptors (GHR, IGF1R and IGF2R) play an important role in the physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of microsatellite markers located in the 5′‐regulatory region of the IGF1 and GHR genes in beef cattle belonging to different genetic groups and to determine effects of these markers on growth and carcass traits in these animals under an intensive production system. For this purpose, genotyping was performed on 384 bulls including 79 Nellore, 30 Canchim (5/8 Charolais + 3/8 Zebu) and 275 crossbred animals originating from crosses of Simmental (1/2 Simmental, n = 30) and Angus (1/2 Angus, n = 245) sires with Nellore females. The effects of substituting L allele for S allele of GHR microsatellite across Nellore, Canchim and 1/2 Angus were significant for weight gain and body weight (P < 0.05). The IGF1 microsatellite allele substitutions of 229 for 225 within Nellore group and of 225 for 229 within 1/2 Angus were not significant for any of the traits.
Myostatinand its implications on animal breeding: a review
Authors: Bellinge R. H. S. , Liberles D. A. , Iaschi S. P. A. , O'Brien P. A. , Tay G. K. 
Published: January 2005

SummaryMyostatin, or growth and differentiation factor 8 (GDF8), has been identified as the factor causing a phenotype known as double muscling, in which a series of mutations render the gene inactive, and therefore, unable to regulate muscle fibre deposition. This phenotype occurs at a high frequency in some breeds of cattle such as Belgian Blue and Peidmontese. Phylogenetic analysis has shown that there has been positive selection pressure for non‐synonymous mutations within themyostatingene family, around the time of the divergence of cattle, sheep and goats, and these positive selective pressures on non‐ancestralmyostatinare relatively recent. To date, there have been reports of nine mutations in coding regions ofmyostatinthat cause non‐synonymous changes, of which three cause missense mutations, including two in exon 1 and one in exon 2. The remaining six mutations, located in exons 2 and 3, result in premature stop codons, which are the mutations responsible for the double‐muscling phenotype. Unfortunately, breed management problems exist for double‐muscled cattle, such as birthing difficulties, which can be overcome through genetically controlled breeding programmes, as shown in this review.
The phylogeny of Chinese indigenous pig breeds inferred from microsatellite markers
Authors: Fang M. , Hu X. , Jiang T. , Braunschweig M. , Hu L. , Du Z. , Feng J. , Zhang Q. , Wu C. , Li N. 
Published: January 2005

SummaryA genetic study of 32 local Chinese, three foreign pig breeds [Duroc (DU), Landrace and Yorkshire], and two types of wild boar (Hainan and Dongbei wild boar) based on 34 microsatellite loci was carried out to clarify the phylogeny of Chinese indigenous pig breeds. The allele frequencies, effective numbers of alleles, and the average heterozygosity within populations were calculated. The results showed that the genetic variability of the Lingao pig was the largest, while the Jiaxing pig was the lowest. The greatest distance between domestic pigs was found between Shanggao and DU pig and the shortest was found between Wuzhishan and Lingao pig, respectively. A neighbour‐joining tree constructed from Modified Cavalli‐Sforza genetic distances divided Chinese pigs into two clusters; four subclusters were also identified. Our results only partly agree with the traditional types of classification and also provide a new relationship among Chinese local pig breeds. Our data also confirmed that Chinese pig breeds have a different origin from European/American breeds and can be utilized in programmes that aim to maintain Chinese indigenous pig breeds.
Localizing the X‐linked orange colour phenotype using feline resource families
Authors: Grahn R. A. , Lemesch B. M. , Millon L. V. , Matise T. , Rogers Q. R. , Morris J. G. , Fretwell N. , Bailey S. J. , Batt R. M. , Lyons L. A. 
Published: January 2005

SummaryMany genes influencing mammalian coat colours are well conserved. While genes responsible for pelage phenotypes in one species provide strong evidence for a candidate gene in a different species, the X‐linked orange phenotype of the domestic cat is unique within mammals. The orange locus (O) undergoes X‐inactivation, producing females that express both wildtype black (wt) and orange (variant) phenotypes when heterozygous (tortoiseshell). The orange locus has not yet been localized on the X chromosome. Tortoiseshell male cats have been identified but have been shown to be sex chromosome trisomies (XXY). To localize the cat orange locus, 10 feline‐derived X‐linked microsatellites were analysed in two extended cat pedigrees consisting of 79 and 55 individuals, respectively, segregating for the orange phenotype. Linkage analyses excluded close association of orange in the vicinity of the nine informative X‐linked microsatellites. One marker was not polymorphic within either family. Several markers suggested exclusion (Z < −2.0) at distances of 7.5–33 cM. Exclusion analyses suggested a possible location for orange a 14 cM region near Xcen. Recombination distances of markers in the segregating feline pedigrees were reduced as compared with the feline interspecies backcross family. Thus, the presented pedigrees may be useful as reference families for the domestic cat because more accurate recombination rates for domestic cats can be determined.
Gene expression of ecdysteroid‐regulated gene E74 of the honeybee in ovary and brain
Authors: Paul R. K. , Takeuchi H. , Matsuo Y. , Kubo T. 
Published: January 2005

AbstractTo facilitate studies of hormonal control in the honeybee (Apis mellifera L.), a cDNA for a honeybee homologue of the ecdysteroid‐regulated gene E74 (AmE74) was isolated and its expression was analysed. Northern blot analysis indicated strong expression in the adult queen abdomen, and no significant expression in the adult drone and worker abdomens. In situ hybridization demonstrated that this gene was expressed selectively in the ovary and gut in the queen abdomen. Furthermore, this gene was also expressed selectively in subsets of mushroom body interneurones in the brain of the adult worker bees. These findings suggest that AmE74 is involved in neural function as well as in reproduction in adult honeybees.
Gene expression profiles among immature and adult reproductive castes of the termite Reticulitermes flavipes
Authors: Scharf M. E. , Wu‐Scharf D. , Zhou X. , Pittendrigh B. R. , Bennett G. W. 
Published: January 2005

AbstractArray‐based genomic studies were conducted with the goal of identifying immature (i.e. nymph) and adult reproductive caste‐biased gene expression in the termite Reticulitermes flavipes. Using cDNA macro‐arrays, we identified thirty‐four nymph‐biased genes falling into eight ontogenic categories. Based on gene expression profiles among diverse castes and developmental stages (determined by quantitative PCR), several important trends emerged. These findings highlight the importance of several developmental and survival‐based factors among immature and adult termite reproductives, including: vitellogenesis, nutrient storage, juvenile hormone sequestration, ribosomal translational and filtering mechanisms, fatty acid biosynthesis, apoptosis inhibition, and both endogenous and symbiont cellulase‐assisted nutrition. These findings are highly significant as they are the first to elucidate the molecular biology underlying termite reproductive caste differentiation and reproductive caste‐specific biology. Other gene expression results are in agreement with previous findings that suggest roles for vitellogenin‐like haemolymph proteins in soldier caste differentiation.
Insect glutathione transferases and insecticide resistance
Authors: Enayati A. A. , Ranson H. , Hemingway J. 
Published: January 2005

AbstractGlutathione transferases (GSTs) are a diverse family of enzymes found ubiquitously in aerobic organisms. They play a central role in the detoxification of both endogenous and xenobiotic compounds and are also involved in intracellular transport, biosynthesis of hormones and protection against oxidative stress. Interest in insect GSTs has primarily focused on their role in insecticide resistance. GSTs can metabolize insecticides by facilitating their reductive dehydrochlorination or by conjugation reactions with reduced glutathione, to produce water‐soluble metabolites that are more readily excreted. In addition, they contribute to the removal of toxic oxygen free radical species produced through the action of pesticides. Annotation of the Anopheles gambiae and Drosophila melanogaster genomes has revealed the full extent of this enzyme family in insects. This mini review describes the insect GST enzyme family, focusing specifically on their role in conferring insecticide resistance.
Aedes aegyptitransferrin. Gene structure, expression pattern, and regulation
Authors: Harizanova N. , Georgieva T. , Dunkov B. C. , Yoshiga T. , Law J. H. 
Published: January 2005

AbstractMosquitoes and all other insects so far examined have an abundant haemolymph transferrin (Tsf). The exact function of these proteins has not been determined, but they may be involved in iron transport, in oogenesis and in innate immune defence against parasites and pathogens. The Tsf gene ofAedes aegyptihas been cloned and sequenced. It contains a single small intron, which contrasts it to vertebrate Tsf genes that contain up to sixteen introns. The promoter region of the gene is rich in putative NF‐κB binding sites, which is consistent with the postulated role of Tsf in insect innate immunity. Tsf message levels are very low in embryos and early larvae, but high in late larvae, pupae and adults. Western blotting experiments revealed high levels of Tsf protein in pupae and adults. Late larvae and ovaries of blood‐fed mosquitoes have little intact protein, but two prominent proteolytic degradation products. These may represent biologically active peptides, as has been shown for other organisms. Tsf message is down‐regulated by inorganic iron in the diet or environment, but up‐regulated by a blood meal in the adult female. The up‐regulation following a blood meal may, in part, be due to the decrease in juvenile hormone (JH) that is known to follow blood feeding. Treatment of blood‐fed females with methoprene, an analogue of JH, resulted in decrease of the Tsf message.
Molecular cloning and transcriptional activation of lysozyme‐encoding cDNAs in the mosquito Aedes aegypti
Authors: Ursic Bedoya R. J. , Mitzey A. M. , Obraztsova M. , Lowenberger C. 
Published: January 2005

AbstractLysozymes are enzymes characterized by their ability to break down bacterial cell walls. In insects certain lysozymes are only found in the midgut, whereas others are only found in the haemolymph and fat body after immune challenge. We identified two lysozyme‐encoding cDNAs from Aedes aegypti. Both deduced protein sequences are basic in nature, contain 148 amino acids including eight highly conserved cysteine residues, and their genomic sequences contain a single intron. Transcriptional profiles indicated that the predominant form is constitutively expressed and up‐regulated upon immune challenge and blood feeding in adult mosquitoes. The second form is expressed during early developmental stages, larvae and pupae, and at low levels in adults after immune challenge. Lysozymes in Aedes aegypti play both roles, defined by the spatial and temporal regulation of their expression.
Expression of Cyp6g1 and Cyp12d1 in DDT resistant and susceptible strains of Drosophila melanogaster
Authors: Festucci‐Buselli R. A. , Carvalho‐Dias A. S. , De Oliveira‐Andrade M. , Caixeta‐Nunes C. , Li H.‐M. , Stuart J. J. , Muir W. , Scharf M. E. , Pittendrigh B. R. 
Published: January 2005

AbstractThe Rst(2)DDT locus (loci) in Drosophila is associated with the over‐expression of two cytochrome P450 genes, Cyp6g1 and Cyp12d1. Using northern and western blot analysis we observed the expression pattern of these two genes in two DDT susceptible (Canton‐S and 91‐C) and three DDT resistant strains (Wisconsin, 91‐R and Hikone‐R). In Canton‐S and 91‐R, the CYP6G1 protein was constitutively expressed throughout development. In the Wisconsin strain, CYP6G1 was not expressed in third instar larvae unless the larvae are exposed to DDT. CYP12D1 protein was only expressed in adults. Cyp12d1 mRNA is induced in DDT resistant strains post‐exposure to DDT and the expression patterns of Cyp12d1 mRNA varied across DDT resistant strains. Our data support the hypothesis that there is evolutionary plasticity in the expression patterns of P450s associated with metabolic pesticide resistance.
Potential causes and life‐history consequences of sexual size dimorphism in mammals
Authors: ISAAC JOANNE L. 
Published: January 2005

ABSTRACT1. Male‐biased sexual size dimorphism (SSD) in mammals has been explained by sexual selection favouring large, competitive males. However, new research has identified other potential factors leading to SSD. The aim of this review is to evaluate current research on the causes of SSD in mammals and to investigate some consequences of SSD, including costs to the larger sex and sexual segregation.2. While larger males appear to gain reproductive benefits from their size, studies have also identified alternative mating strategies, unexpected variance in mating success and found no clear relationship between degree of polygyny and dimorphism. This implies that sexual selection is unlikely to be the single selective force directing SSD.3. Latitude seems to influence SSD primarily through variation in overall body size and seasonal food availability, which affect potential for polygyny. Likewise, population density influences resource availability and evidence suggests that food scarcity differentially constrains the growth of the sexes. Diverging growth patterns between the sexes appear to be the primary physiological mechanism leading to SSD.4. Female‐biased dimorphism is most adequately explained by reduced male–male competition resulting in a decrease in male size. Female–female competition for dominance and resources, including mates, may also select for increased female size.5. Most studies found that sexual segregation arises through asynchrony of activity budgets between the sexes. The larger sex can suffer sex‐biased mortality through increased parasite load, selective predation and the difficulty associated with sustaining a larger body size under conditions of resource scarcity.6. None of the variables considered here appears to contribute a disproportionate amount to SSD in mammals. Several promising avenues of research are currently overlooked and long‐term studies, which have previously been biased toward ungulates, should be carried out on a variety of taxa.
The response of mammals to forest fire and timber harvest in the North American boreal forest
Authors: FISHER JASON T. , WILKINSON LISA 
Published: January 2005

ABSTRACT1. This paper reviews and compares the effects of forest fire and timber harvest on mammalian abundance and diversity, throughout successional time in the boreal forest of North America.2. Temporal trends in mammal abundance and diversity are generally similar for both harvested and burned stands, with some differences occurring in the initiation stage (0–10 years post disturbance).3. Small mammals and ungulates are most abundant immediately post disturbance, and decrease as stands age. Lynxes and hares utilize mid‐successional stands, but are rare in young and old stands. Bats, arboreal sciurids and mustelids increase in abundance with stand age, and are most abundant in old growth.4. Substantial gaps in the data exist for carnivores; the response of these species to fire and harvest requires research, as predator–prey interactions can affect mammal community structure in both early and late successional stages.5. The lack of explicit treatment of in‐stand forest structure post disturbance, in the reviewed literature made comparisons difficult. Where forest structure was considered, the presence of downed woody material, live residual trees and standing dead wood were shown to facilitate convergence of mammal communities to a pre‐disturbance state for both disturbance types.6. Mammalian assemblages differed considerably between successional stages, emphasizing the importance of maintaining stands of each successional stage on the landscape when implementing forest management strategies.
Population status, trends and a re‐examination of the hypotheses explaining the recent declines of the southern elephant seal Mirounga leonina
Authors: MCMAHON CLIVE R. , BESTER MARTHÁN N. , BURTON HARRY R. , HINDELL MARK A. , BRADSHAW COREY J. A. 
Published: January 2005

ABSTRACT 1. Between the 1950s and 1990s the southern elephant seal Mirounga leonina underwent large decreases in population size throughout most of its breeding range in the Southern Ocean. While current population estimates suggest a recent recovery, some breeding populations have continued to decrease in recent years (Macquarie and Marion Islands), others have either remained stable (South Georgia, Kerguelen and Heard Island) or have increased (Peninsula Valdés, Argentina). 2. Intrinsic hypotheses for patterns of regional decline include factors that are affected by density‐dependent mechanisms: (i) paucity of males, (ii) population ‘overshoot’ and (iii) pandemic disease. Extrinsic hypotheses include (iv) predation, (v) competition with fisheries concerns, (vi) interspecific competition, (vii) environmental change and (viii) human disturbance. Of the eight hypotheses proposed and examined here, we conclude that three can be discounted (i, v, viii), three are unlikely, but may require more testing (ii, iii, iv) and two are plausible (vi, vii). 3. The interspecific competition hypothesis is difficult to test because it requires the simultaneous monitoring of species that overlap directly with elephant seals, many of which have not been identified or little is known. However, an analysis of the relationship between log variance and log abundance (Taylor's power law) for populations of southern and northern elephant seals suggests that interspecific competition is not a significant factor in the decline of the southern elephant seal. 4. The hypothesis that decreases in southern elephant seal populations between the 1950s and 1990s were caused by the environmental change is the easiest to test and most plausible of the hypotheses. We propose a framework by which to test this hypothesis to determine how food availability affects individual survival.
A quantitative analysis of the abundance and demography of European hares Lepus europaeus in relation to habitat type, intensity of agriculture and climate
Authors: SMITH REBECCA K. , VAUGHAN JENNINGS NANCY , HARRIS STEPHEN 
Published: January 2005

ABSTRACT 1. European hares Lepus europaeus have declined throughout Europe since the 1960s. Possible reasons for this include agricultural intensification and changes in climate and predator numbers, but no clear consensus has been reached as to the relative importance of each of these. We aimed to identify factors associated with high and low hare numbers throughout Europe, to determine which could have caused population declines. 2. Results of 77 research papers from 12 European countries were summarized. Relationships between hare density and demographics and habitat, climate, hunting and predator variables were examined and quantified where possible. Temporal changes in factors identified as being associated with high or low numbers of hares were then examined to see if they could explain population declines. 3. Data from pastural habitats were limited, but densities of hares were low. Arable habitats had higher densities than mixed areas in spring, unless farming was intensive in which case densities were similar. In autumn the two habitats had similar densities. Field size, temperature, precipitation and hunting had no effect on density throughout Europe. Fecundity was affected by climate. 4. Arable land, various crops, fallow habitat and temperature were positively associated, and monoculture, precipitation and predators negatively associated with hare abundance. The relationship of field size, pasture and woodland with abundance depended on spatial scale. 5. Habitat changes caused by agricultural intensification are the ultimate cause of hare population declines. Effects of changes in climate or predator numbers are magnified by the loss of high‐quality year‐round forage and cover. Further research is required on how habitat changes affect fecundity and survival, and to identify which parameters have the greatest impact on population numbers. Farmland management policies that target the re‐establishment of some of the habitat diversity lost within fields, farms and landscapes will help to reverse the decline of the European hare.
INVITED REVIEW: Quantitative trait locus mapping in natural populations: progress, caveats and future directions
Authors: SLATE JON 
Published: January 2005

AbstractOver the last 15 years quantitative trait locus (QTL) mapping has become a popular method for understanding the genetic basis of continuous variation in a variety of systems. For example, the technique is now an integral tool in medical genetics, livestock production, plant breeding and population genetics of model organisms. Ten years ago, it was suggested that the method could be used to understand continuous variation in natural populations. In this review I: (i) clarify what is meant by natural population in the QTL context, (ii) discuss whether evolutionary biologists have successfully mapped QTL in natural populations, (iii) highlight some of the questions that have been addressed by QTL mapping in natural populations, (iv) describe how QTL mapping can be conducted in unmanipulated natural populations, (v) highlight some of the limitations of QTL mapping and (vi) try to predict some future directions for QTL mapping in natural populations.