bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology and identification of first instars of the European and Mediterranean blowflies of forensic importance. Part I: Chrysomyinae
Authors: SZPILA K. , HALL M. J. R. , SUKONTASON K. L. , TANTAWI T. I.
Published: July 2012

Light microscopy photographs, line illustrations and scanning electron micrographs are provided for first instars of Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius) and Protophormia terraenovae (Robineau‐Desvoidy) (all: Diptera: Calliphoridae). The following morphological structures are documented: pseudocephalon; antennal complex; maxillary palpus; facial mask; thoracic and abdominal spinulation; spiracular field; posterior spiracles, and cephaloskeleton. New diagnostic features of the cephaloskeleton and the spinulation of abdominal segments are described. Verification of earlier descriptions revealed major discrepancies among published data. The present results allow for the clarification, correction and, especially, complementation of existing information provided by numerous authors. Finally, an identification key for first‐instar larvae of European and Mediterranean Chrysomyinae of forensic importance is presented.
Age‐specific changes in sperm levels among female tsetse (Glossina spp.) with a model for the time course of insemination
Authors: HARGROVE JOHN W.
Published: July 2012

The age, insemination and ovulation status of tsetse flies Glossina pallidipes Austen (n = 154369) and Glossina morsitans morsitans Westwood (n = 19659), captured over 11 years in Zimbabwe, are assessed by ovarian dissection. Instantaneous rates of insemination increase exponentially with age in both species; 90% insemination levels are reached after 5 days post‐emergence in G. m. morsitans and 7 days in G. pallidipes, varying little with season. More than 95% of both species have ovulated by the age of 8 days and 99% by 12 days. Older flies that have not ovulated are > 100‐fold more likely to be caught in October and November than in other months. A 500‐fold decrease in trap catches did not result in any detectible decrease in the probability of females being inseminated. The proportion of partially filled spermathecae rises for approximately 6 days then declines, consistent with some flies having mated more than once. For flies caught on electric nets, with wings undamaged during capture, wing‐fray data are used to extend ovarian age estimates up to 11 ovulations. Among these flies, the volume of sperm in the spermathecae declines little in flies that have ovulated up to seven times; thereafter, it declines by approximately 1% per ovulation. The time course of insemination and the mating frequency of females are important considerations in modelling tsetse fly populations, as well as for the dynamics of interventions involving the release of genetically‐modified insects, which should not be seriously compromised by the limited levels of polyandry currently observed.
Screening patients with Diabetes Mellitus for Tuberculosis in China
Authors: Lin Yan , Li Liang , Mi Fengling , Du Juan , Dong Yaqiong , Li Zhaoliang , Qi Wenbo , Zhao Xiangling , Cui Ying , Hou Fengying , Zachariah Rony , Kapur Anil , Lönnroth Knut , Harries Anthony D.
Published: July 2012

Objective  There is a high burden of both diabetes (DM) and tuberculosis (TB) in China, and as DM increases the risk of TB and adversely affects TB treatment outcomes, there is a need for bidirectional screening of the two diseases. How this is best performed is not well determined. In this pilot project in China, we aimed to assess the feasibility and results of screening DM patients for TB within the routine healthcare setting of five DM clinics.

Method  Agreement on how to screen, monitor and record was reached in May 2011 at a national stakeholders meeting, and training was carried out for staff in the five clinics in July 2011. Implementation started in September 2011, and we report on 7 months of activities up to 31 March 2012. DM patients were screened for TB at each clinic attendance using a symptom‐based enquiry, and those positive to any symptom were referred for TB investigations.

Results  In the three quarters, 72% of 3174 patients, 79% of 7196 patients and 68% of 4972 patients were recorded as having been screened for TB, resulting in 7 patients found who were already known to have TB, 92 with a positive TB symptom screen and 48 of these newly diagnosed with TB as a result of referral and investigation. All patients except one were started on anti‐TB treatment. TB case notification rates in screened DM patients were several times higher than those of the general population, were highest for the five sites combined in the final quarter (774/100 000) and were highest in one of the five clinics in the final quarter (804/100 000) where there was intensive in‐house training, special assignment of staff for screening and colocation of services.

Conclusion  This pilot project shows that it is feasible to carry out screening of DM patients for TB resulting in high detection rates of TB. This has major public health and patient‐related implications.
Physiological adaptation along environmental gradients and replicated hybrid zone structure in swordtails (Teleostei:Xiphophorus)
Authors: Culumber Z.W. , Shepard D.B. , Coleman S.W. , Rosenthal G.G. , Tobler M.
Published: July 2012

Local adaptation is often invoked to explain hybrid zone structure, but empirical evidence of this is generally rare. Hybrid zones between two poeciliid fishes,Xiphophorus birchmanniandX. malinche,occur in multiple tributaries with independent replication of upstream‐to‐downstream gradients in morphology and allele frequencies. Ecological niche modelling revealed that temperature is a central predictive factor in the spatial distribution of pure parental species and their hybrids and explains spatial and temporal variation in the frequency of neutral genetic markers in hybrid populations. Among populations of parentals and hybrids, both thermal tolerance and heat‐shock protein expression vary strongly, indicating that spatial and temporal structure is likely driven by adaptation to local thermal environments. Therefore, hybrid zone structure is strongly influenced by interspecific differences in physiological mechanisms for coping with the thermal environment.
Genetic differences and phenotypic plasticity in body size between high‐ and low‐altitude populations of the ground beetle Carabus tosanus
Authors: Tsuchiya Y. , Takami Y. , Okuzaki Y. , Sota T.
Published: July 2012

The body size of a univoltine carabid beetle Carabus tosanus on Shikoku Island, Japan, was clearly smaller in higher‐altitude populations (subspecies), which possibly represents incipient speciation. To explore the determinants of altitudinal differences in body size in this species, we studied the degree of phenotypic plasticity by conducting rearing experiments at two constant temperatures and examined genetic differences through interpopulation crosses. At 15 °C, C. tosanus had a longer developmental period and a shorter adult body than at 20 °C. Nevertheless, variation in body size due to temperature effects (phenotypic plasticity) was small compared to the interpopulation differences, which suggests substantial genetic differences between populations (subspecies) at different altitudes. In F1 offspring from crosses between a low‐altitude (subspecies tosanus) and a high‐altitude population (subspecies ishizuchianus), adult body length was affected by the genotypes of both parents, with an interaction effect of parental genotype and offspring sex. Further analyses revealed that adult body length was affected by sex‐linked factors in addition to autosomal factors. These genetic differences in body size may have resulted from adaptations to different altitudes and may be important for the process of incipient speciation because body size differences could contribute to premating reproductive isolation.
The costs of parental care: a meta‐analysis of the trade‐off between parental effort and survival in birds
Authors: Santos E. S. A. , Nakagawa S.
Published: July 2012

A fundamental premise of life‐history theory is that organisms that increase current reproductive investment suffer increased mortality. Possibly the most studied life‐history phenotypic relationship is the trade‐off between parental effort and survival. However, evidence supporting this trade‐off is equivocal. Here, we conducted a meta‐analysis to test the generality of this tenet. Using experimental studies that manipulated parental effort in birds, we show that (i) the effect of parental effort on survival was similar across species regardless of phylogeny; (ii) individuals that experienced reduced parental effort had similar survival probabilities than control individuals, regardless of sex; and (iii) males that experienced increased parental effort were less likely to survive than control males, whereas females that experienced increased effort were just as likely to survive as control females. Our results suggest that the trade‐off between parental effort and survival is more complex than previously assumed. Finally, our study provides recommendations of unexplored avenues of future research into life‐history trade‐offs.
First Report of Soil‐Borne Wheat Mosaic Virus (SBWMV)‐Infecting Triticale in Poland
Authors: Trzmiel Katarzyna , Jeżewska Małgorzata , Zarzyńska Aleksandra
Published: July 2012

The virus in naturally infected, stunted triticale plants was identified as soil‐borne wheat mosaic virus (SBWMV). The infected plants were collected in the Southern Wielkopolska region (Western Poland). Molecular analysis including RT‐PCR, and sequencing of the complete coding sequence of coat protein gene, was performed. The sequence of the Polish isolate of SBWMV (SBWMV‐Pol1) shared 100, 99 and 98% identities with the corresponding regions of De1 (AF519799), OKL‐1 (X81639) and US‐Nebraska (L07938) isolates of SBWMV, respectively. Phylogenetic analyses showed that the Polish isolate, SBWMV‐Pol1, clustered together with other SBWMV isolates. This is the first report of the occurrence of SBWMV in Poland and the second of its presence in Europe.
The Simmet Lecture: New Horizons on an Old Landscape – Oxidative Stress, DNA Damage and Apoptosis in the Male Germ Line
Authors: Aitken RJ , De Iuliis GN , Gibb Z , Baker MA
Published: July 2012

Contents

Our ability to diagnose and treat male infertility is gradually improving in concert with advances in our understanding of the molecular mechanisms underpinning defective sperm function. In this context, one of the factors to emerge as a major causative agent in male infertility is oxidative stress. Spermatozoa are particularly susceptible to such stress because they are exceptionally rich in vulnerable substrates such as polyunsaturated fatty acids, proteins and DNA. The lack of sperm cytoplasm also provides these cells with little capacity to protect themselves from oxidative attack or to effect any repair, should damage occur. Similarly, sperm chromatin is in a quasi‐crystalline state and has very little capacity to respond to any DNA damage induced by oxidative attack. When the latter does occur, it appears to be initiated by reactive oxygen species (ROS) generated by the sperm mitochondria. These free radicals attack the lipids present in the sperm mitochondria generating electrophilic aldehydes, which bind to components of the mitochondrial electron transport chain stimulating yet more ROS production. The oxidative stress created via this self‐propagating mechanism initiates an apoptotic cascade as a result of which the spermatozoa loose their capacity for fertilization and suffer damage to their DNA. Phosphatidylserine externalization is a late event in sperm apoptosis and may facilitate the silent phagocytosis of moribund cells in the female reproductive tract, that is, the phagocytosis of senescent spermatozoa without the accompanying generation of an inflammatory response. Encouragingly, the involvement of oxidative stress in the aetiology of male infertility has opened up new opportunities for therapeutic interventions involving the judicious administration of nucleophiles and other forms of antioxidants.
Effects of Maternal Environment During Gestation on Ovarian Folliculogenesis and Consequences for Fertility in Bovine Offspring
Authors: Evans ACO , Mossa F , Walsh SW , Scheetz D , Jimenez‐Krassel F , Ireland JLH , Smith GW , Ireland JJ
Published: July 2012

Contents

Mammals such as cattle, swine, sheep and humans are born with a highly variable number of ovarian follicles and oocytes in the ovaries that dwindle during ageing and are never replenished. This variation in the ovarian reserve is reflected in the numbers of antral follicles in the ovaries at all ages after birth. As numbers of follicles in ovaries are determined during gestation, the role of maternal nutrition and health during gestation (at time of ovarian development in their foetuses) has been investigated as factors that may impact oogonia proliferation and thus follicle numbers post‐natally. These studies have found that both nutrition and health impact numbers of follicles in their offspring. The idea that numbers of follicles and oocytes in ovaries impact fertility is a long‐held belief in reproductive biology. This has recently been tested in cattle, and it has been shown that cows with a relatively high number of antral follicles in ovaries have higher pregnancy rates, shorter calving to conception intervals and fewer artificial inseminations during the breeding season compared with cows with a lower number of follicles, and similarly, heifers with many follicles had higher pregnancy rates than those with fewer follicles. Studies summarized in this review highlight the importance of the maternal environment during gestation in determining the size of the ovarian reserve in their offspring and also the contribution of the ovarian reserve to subsequent fertility in cattle.
Reproductive Science in the Global Village
Authors: Chenoweth PJ
Published: July 2012

Contents

Livestock production contributes not only to national economies, but also to sustainability and profitability of agriculture, as well as to the fabric of local societies. Efficient and viable animal production systems are dependent upon the effective management of animal reproduction. Similar arguments can be made in support of the importance of reproduction for companion and performance animals, whereas its key role in preserving endangered species is indisputable. Despite such considerations, the widespread dissemination of current and credible information regarding animal reproduction faces challenges, not only in the developing world, but also in developed countries, where animal reproduction education is apparently in decline. This review will examine these issues, as well as various ways in which animal reproduction education and knowledge transfer is currently being pursued throughout the world. It will conclude with suggested avenues and opportunities for improvement.
Developmental and Epigenetic Anomalies in Cloned Cattle
Authors: Smith LC , Suzuki J , Goff AK , Filion F , Therrien J , Murphy BD , Kohan‐Ghadr HR , Lefebvre R , Brisville AC , Buczinski S , Fecteau G , Perecin F , Meirelles FV
Published: July 2012

Contents

Many of the developmental anomalies observed in cloned animals are related to foetal and placental overgrowth, a phenomenon known as the ‘large offspring syndrome’ (LOS) in ruminants. It has been hypothesized that the epigenetic control of imprinted genes, that is, genes that are expressed in a parental‐specific manner, is at the root of LOS. Our recent research has focused on understanding epigenetic alterations to imprinted genes that are associated with assisted reproductive technologies (ART), such as early embryo in vitro culture (IVC) and somatic cell nuclear transfer (SCNT) in cattle. We have sought and identified single nucleotide polymorphisms in Bos indicus DNA useful for the analysis of parental‐specific alleles and their respective transcripts in tissues from hybrid embryos derived by crossing Bos indicus and Bos taurus cattle. By analysing differentially methylated regions (DMRs) of imprinted genes SNRPN, H19 and the IGF2R in cattle, we demonstrated that there is a generalized hypomethylation of the imprinted allele and the biallelic expression of embryos produced by SCNT when compared to the methylation patterns observed in vivo (artificially inseminated). Together, these results indicate that imprinting marks are erased during the reprogramming of the somatic cell nucleus during early development, indicating that such epigenetic anomalies may play a key role in mortality and morbidity of cloned animals.
Lessons Learned from Cloning Dogs
Authors: Kim MJ , Oh HJ , Kim GA , Park JE , Park EJ , Jang G , Ra JC , Kang SK , Lee BC
Published: July 2012

Contents

The aim of this article is to review dog cloning research and to suggest its applications based on a discussion about the normality of cloned dogs. Somatic cell nuclear transfer was successfully used for production of viable cloned puppies despite limited understanding of in vitro dog embryo production. Cloned dogs have similar growth characteristics to those born from natural fertilization, with no evidence of serious adverse effects. The offspring of cloned dogs also have similar growth performance and health to those of naturally bred puppies. Therefore, cloning in domestic dogs can be applied as an assisted reproductive technique to conserve endangered species, to treat sterile canids or aged dogs, to improve reproductive performance of valuable individuals and to generate disease model animals.
Agency Perspectives on Food Safety for the Products of Animal Biotechnology
Authors: Howard HJ , Jones KM , Rudenko L
Published: July 2012

Contents

Animal biotechnology represents one subset of tools among a larger set of technologies for potential use to meet increasing world demands for food. Assisted reproductive technologies (ART) such as artificial insemination and embryo transfer continue to make positive contributions in food animal production. The US Food and Drug Administration (FDA) performed a comprehensive risk assessment to identify potential food consumption or animal health risks associated with animal cloning, an emerging ART. At that time, FDA concluded that animal cloning posed no unique risks either to animal health or to food consumption, and food from animal clones and their sexually reproduced offspring required no additional federal regulation beyond that applicable to conventionally bred animals of the species examined. At this time, no new information has arisen that would necessitate a change in FDA’s conclusions on food from animal clones or their sexually reproduced offspring. Use of recombinant DNA technologies to produce genetically engineered (GE) animals represents another emerging technology with potential to impact food animal production. In its regulation of GE animals, FDA follows a cumulative, risk‐based approach to address scientific questions related to the GE animals. FDA evaluates data and information on the safety, effectiveness and stability of the GE event. FDA carries out its review at several levels (e.g. molecular biology, animal safety, food safety, environmental safety and claim validation). GE animal sponsors provide data to address risk questions for each level. This manuscript discusses FDA’s role in evaluation of animal cloning and GE animals.
Manipulation of Follicle Development to Ensure Optimal Oocyte Quality and Conception Rates in Cattle
Authors: Baruselli PS , Sá Filho MF , Ferreira RM , Sales JNS , Gimenes LU , Vieira LM , Mendanha MF , Bó GA
Published: July 2012

Contents

Over the last several decades, a number of therapies have been developed that manipulate ovarian follicle growth to improve oocyte quality and conception rates in cattle. Various strategies have been proposed to improve the responses to reproductive biotechnologies following timed artificial insemination (TAI), superovulation (SOV) or ovum pickup (OPU) programmes. During TAI protocols, final follicular growth and size of the ovulatory follicle are key factors that may significantly influence oocyte quality, ovulation, the uterine environment and consequently pregnancy outcomes. Progesterone concentrations during SOV protocols influence follicular growth, oocyte quality and embryo quality; therefore, several adjustments to SOV protocols have been proposed depending on the animal category and breed. In addition, the success of in vitro embryo production is directly related to the number and quality of cumulus oocyte complexes harvested by OPU. Control of follicle development has a significant impact on the OPU outcome. This article discusses a number of key points related to the manipulation of ovarian follicular growth to maximize oocyte quality and improve conception rates following TAI and embryo transfer of in vivo‐ and in vitro‐derived embryos in cattle.
Factors Affecting Oocyte and Embryo Transcriptomes
Authors: Sirard M‐A
Published: July 2012

Contents

The most important factor affecting the oocyte and early embryo transcriptome is the legacy from the follicular environment prior to meiotic resumption. Up to the 8‐cell stage, the oocyte responds to maternal instructions stored before resumption of the meiotic division. Recent evidence suggests that properly prepared or programmed oocytes (in vivo) can achieve close to 100% blastocyst rates in standard in vitro conditions/media. Therefore, the optimal oocyte requires perfect follicular timing and differentiation, but the intra‐oocyte mechanisms involved in such preparation are not completely understood. In addition, the influence of maternal mRNA storage and degradation, as well as the length of the poly A tail that influences the general pattern of the oocyte/early embryo transcriptome, is an important factor. Several hypotheses have been put forth to explain the depletion of the maternal store, including the potential role of microRNA (miRNA) in this process. The activation of the embryonic genome could be dependent on, or associated with, the process of maternal mRNA degradation, but obviously other functions are being activated at this critical time point. This review will focus on the period from full‐size oocytes to the eight‐cell stage and will summarize the impact of the important factors, that is, follicle, maternal RNA storage and embryonic genome activation, on the transcriptome.
Role of the Oviduct in Early Embryo Development
Authors: Besenfelder U , Havlicek V , Brem G
Published: July 2012

Contents

This review highlights the role of the oviduct in early embryo development, which has to fulfil many aligned and well‐tuned tasks during early embryogenesis. The oviductal lining is subjected to dynamic changes to timely accomplish gamete transport, fertilization and embryo development and to deliver a competent and healthy conceptus to the endometrium which can implant and develop to term. Although knowledge about the role of the oviduct is limited, we know that embryos are very sensitive to the environment in which they develop. The success of in vitro embryo production techniques demonstrates that it is possible to bypass the oviduct during early development and, to a certain extent, replicate the conditions in vitro. However, comparative studies show that embryos developed in vivo are superior to their in vitro produced counterparts, underlining our relatively poor knowledge of the biology of the oviduct. Oviduct activity is orchestrated by various factors, depending on cyclic dynamics, which crucially affect the success of tubal transfer and/or (re‐)collection of embryos in embryo transfer studies. This paper reviews data which demonstrate that in vivo culture of embryos in the bovine oviduct is a useful tool for the assessment of embryos developed under various conditions (e.g. superovulation vs single ovulation, lactating dairy cows vs non‐lactating cows). It is concluded that more work in the field of early embryo development within the oviduct would contribute to improved ART protocols leading to healthy pregnancies and offspring.
The Effects of Increased Testicular Temperature on Testis‐Specific Isoform of Na+/K+‐ATPase in Sperm and its Role in Spermatogenesis and Sperm Function
Authors: Thundathil JC , Rajamanickam GD , Kastelic JP , Newton LD
Published: July 2012

Contents

Impaired testicular thermoregulation is commonly implicated in abnormal spermatogenesis and impaired sperm function in animals and humans, with outcomes ranging from subclinical infertility to sterility. Bovine testes must be maintained 4–5°C below body‐core temperature for normal spermatogenesis. The effects of elevated testicular temperature have been extensively studied in cattle using a scrotal insulation model, which results in abnormal spermatogenesis and impaired sperm morphology and function. Using this model and proteomic approaches, we compared normal and abnormal sperm (from the same bulls) to elucidate the molecular basis of impaired function. We identified a cohort of sperm functional proteins differentially expressed between normal vs abnormal sperm, including a testis‐specific isoform of Na+/K+‐ATPase. In addition to its role as a sodium pump regulating sperm motility, Na+/K+‐ATPase is also involved as a signalling molecule during sperm capacitation. In conclusion, because of its involvement in regulation of sperm function, this protein has potential as a fertility marker. Furthermore, comparing normal vs abnormal sperm (induced by scrotal insulation) is a useful model for identifying proteins regulating sperm function.
The Emerging Pathophysiology of Age‐related Testicular Degeneration with a Focus on the Stallion and an Update on Potential Therapies
Authors: Turner RM , Zeng W
Published: July 2012

Contents

Studies in laboratory rodents are shedding light on the pathophysiology of testicular ageing and now suggest a complicated basis for age‐related declines in testicular function. A highly significant contributor to infertility may involve failure of specific and complex testicular microenvironments (niches) comprised of a variety of cellular and molecular components. Our laboratory has applied testis tissue xenografting to the study of testicular ageing in the stallion. Using this technique, we have confirmed that the disease is tissue autologous. As would be expected from a tissue autologous disease, hormonal and non‐hormonal therapies designed to drive the function of the diseased testis are ineffective. However, we have some evidence that contact with young, normal testicular tissue may improve the condition of aged, degenerate testes. Perhaps, paracrine factors from young testicular cells may partially restore a young microenvironment and allow for the maintenance of testicular function. These findings form the basis for future studies designed to determine whether cells, genes or proteins from a normal testis can aid the function of a degenerate testis.
Biological Characteristics of Fish Germ Cells and their Application to Developmental Biotechnology
Authors: Yoshizaki G , Okutsu T , Morita T , Terasawa M , Yazawa R , Takeuchi Y
Published: July 2012

Content

We have revealed several unique characteristics of germ cell development using rainbow trout, including the fact that spermatogonia transplanted into the peritoneal cavity of newly hatched embryos migrate toward recipient gonads, that spermatogonia transplanted into female recipients start oogenesis and produce functional eggs and that diploid germ cells transplanted into triploid trout can complete gametogenesis. By combining these unique features of fish germ cells, we established allogeneic and xenogeneic transplantation systems for spermatogonia in several fish species. Spermatogonia isolated from the mature testes of vasa‐green fluorescent protein (Gfp) transgenic rainbow trout were transplanted into the peritoneal cavity of triploid masu salmon newly hatched embryos. These spermatogonia migrated toward recipient salmon genital ridges with extending pseudopodia and were subsequently incorporated into them. We further confirmed that the donor‐derived spermatogonia resumed gametogenesis and produced sperm and eggs in male and female salmon recipients, respectively. By inseminating the resulting eggs and sperm, we obtained only rainbow trout offspring in the F1 generation, suggesting that the triploid salmon recipients produced functional gametes derived only from donor trout. We further confirmed that this intra‐peritoneal transplantation of germ cells is applicable to several marine fishes, which could be of benefit in the production of bluefin tuna that has a large broodstock (>100 kg) and is difficult to maintain in captivity. Gamete production of bluefin tuna could be more easily achieved by generating a surrogate species, such as mackerel, that can produce tuna gametes.
Seminal Plasma and its Effect on Ruminant Spermatozoa During Processing
Authors: Leahy T , de Graaf SP
Published: July 2012

Contents

Seminal plasma can both inhibit and stimulate sperm function, making its use as a supportive medium somewhat contradictory. These effects are directed by the multifunctional action of numerous inorganic and organic components, but it is the direct association of seminal plasma proteins with the sperm membrane that is thought to exert the most significant response. In vitro handling of spermatozoa in preparation for artificial insemination may involve washing, dilution, cooling, freezing, re‐warming and sex‐sorting. These processes can alter proteins of the sperm surface and reduce seminal plasma in the sperm environment. This, among other factors, may destabilize the sperm membrane and reduce the fertilizable lifespan of spermatozoa. Such handling‐induced damage may be prevented or reversed through supplementation of seminal plasma, but the effectiveness of this technique differs with species, and the source and subsequent treatment of both spermatozoa and seminal plasma. Seminal plasma appears to act as a protective medium during in vitro processing of ram spermatozoa, but this does not appear to be the case for bull spermatozoa. The reasons for this divergent effect will be discussed with particular emphasis on the influence of the major proteins of ruminant seminal plasma, known as BSP proteins. The biochemical and biophysical properties of these proteins are well documented, and this information has provided greater insight into the signalling pathways of capacitation and the protective action of extender components.
Effects of Surgical Sterilization on Canine and Feline Health and on Society
Authors: Root Kustritz MV
Published: July 2012

Contents

Surgical sterilization of dogs and cats is a well‐accepted measure for population control in some countries, but is considered unethical as an elective surgery in other countries. This is a review of what is known regarding positive and negative effects of gonadectomy surgery on individual animals and on societal management of unowned dog and cat populations.
Selective Breeding in Fish and Conservation of Genetic Resources for Aquaculture
Authors: Lind CE , Ponzoni RW , Nguyen NH , Khaw HL
Published: July 2012

Content

To satisfy increasing demands for fish as food, progress must occur towards greater aquaculture productivity whilst retaining the wild and farmed genetic resources that underpin global fish production. We review the main selection methods that have been developed for genetic improvement in aquaculture, and discuss their virtues and shortcomings. Examples of the application of mass, cohort, within family, and combined between‐family and within‐family selection are given. In addition, we review the manner in which fish genetic resources can be lost at the intra‐specific, species and ecosystem levels and discuss options to best prevent this. We illustrate that fundamental principles of genetic management are common in the implementation of both selective breeding and conservation programmes, and should be emphasized in capacity development efforts. We highlight the value of applied genetics approaches for increasing aquaculture productivity and the conservation of fish genetic resources.
Nutritional Influences on Folliculogenesis
Authors: Hernandez‐Medrano JH , Campbell BK , Webb R
Published: July 2012

Contents

Folliculogenesis is an intricate process that involves the proliferation and differentiation of both somatic and germ cells. This process depends on complex interactions between systemic factors such as both pituitary gonadotrophins and metabolic hormones and/or local factors produced by the ovarian somatic and germ cells, such as the IGF system and TGF‐β superfamily members. In domestic ruminants, follicular development begins during foetal life with formation of primordial follicles from the association of germ cells and pre‐granulosa cells. After follicular formation, folliculogenesis begins with a primordial follicle progressing into more developed stages (i.e. primary, secondary, pre‐antral and antral) in a continuous, progressive process to either ovulation or, as in most cases, to atresia. Even early stages of follicular formation and subsequent development are influenced by both internal (e.g. genotype) and/or external environmental (e.g. nutrition and season) factors. Among these external factors, nutrition is one of the most important affecting reproductive function, and this is the focus of this review, because other reviews in this issue discuss other environmental factors. A number of studies have now shown that nutrition can have both positive and negative effects on follicular growth, oestrous activity, oocyte quality, blastocyst development and pregnancy outcome. Therefore, understanding the intricate processes involved during folliculogenesis and the ways in which factors, such as nutrition, affect them is leading to new opportunities to improve pregnancy rates by influencing follicle development and oocyte quality. This review will focus on follicular development from foetal to adult stages and the influences that nutrition has during some of these developmental stages.
Follicle Selection in the Avian Ovary
Authors: Johnson PA
Published: July 2012

Contents

Follicle development in the highly efficient laying hen is characterized by a well‐organized follicular hierarchy. This is not the case in other chickens such as the broiler breeder hen that has excessive follicle development and lower reproductive efficiency. Although management practices can optimize egg production in less productive breeds of chickens, the factors that contribute to this difference are not known. Interactions between the oocyte and surrounding somatic cells are believed to be involved in promoting follicle selection. Anti‐Müllerian hormone (AMH) has been shown to have a role in regulating rate of follicle development in mammals. In hens, the expression of AMH is restricted to the growing population of follicles and, similar to mammals, is markedly decreased at around the time of follicle selection. The oocyte factors, growth and differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), have been identified in the hen, and their expression pattern has been characterized. Anti‐Müllerian hormone expression in hens is decreased by a protein factor from the oocyte (not GDF9) and is also decreased by vitamin D. Associated with the decrease in AMH expression by vitamin D, follicle‐stimulating hormone receptor mRNA is increased. These data suggest that information about AMH regulation may enhance our understanding of follicle selection, particularly in birds with aberrant follicle development.
Should Weaning be the Start of the Reproductive Cycle in Hyper‐prolific Sows? A Physiological View
Authors: Kemp B , Soede NM
Published: July 2012

Contents

Normally, sows are in anoestrus during lactation and start their new cycle at the day of weaning. Modern hybrid primiparous sows that suckle large numbers of piglets may lose substantial amounts of body reserves during lactation. This compromises follicle development during lactation. As modern sows have short weaning‐to‐oestrus intervals, these compromised follicles are recruited for ovulation directly after weaning, resulting in lower ovulation rates and lower embryo survival. Postponing or skipping first oestrus after weaning in primiparous sows may help to limit the negative consequences of lactation on subsequent reproduction. Multiparous sows may have very high litter sizes, especially after long lactations as applied in organic sows. These high litter sizes compromise piglet birthweight and survival and subsequent performance. Inducing lactation oestrus in multiparous sows may help to limit litter size and improve piglet survival and performance. This study discusses physiological and reproductive effects of extending the start of a new pregnancy after lactation in primiparous sows and induction of lactation oestrus in multiparous sows. We thereby challenge the view that weaning is an ideal start for the reproductive cycle in modern sows.
Impact of Metal Nanoparticles on Germ Cell Viability and Functionality
Authors: Taylor U , Barchanski A , Kues W , Barcikowski S , Rath D
Published: July 2012

Contents

Metal nanoparticles play an increasing role in consumer products, biomedical applications and in the work environment. Therefore, the effects of nanomaterials need to be properly understood. This applies especially to their potential reproductive toxicology (nanoreprotoxicity), because any shortcomings in this regard would be reflected into the next generation. This review is an attempt to summarize the current knowledge regarding the effects of nanoparticles on reproductive outcomes. A comprehensive collection of significant experimental nanoreprotoxicity data is presented, which highlight how the toxic effect of nanoparticles can be influenced, not only by the particles’ chemical composition, but also by particle size, surface modification, charge and to a considerable extent on the experimental set‐up. The period around conception is characterized by considerable cytological and molecular restructuring and is therefore particularly sensitive to disturbances. Nanoparticles are able to penetrate through biological barriers into reproductive tissue and at least can have an impact on sperm vitality and function as well as embryo development. Particularly, further investigations are urgently needed on the repetitively shown effect of the ubiquitously used titanium dioxide nanoparticles on the development of the nervous system. It is recommended that future research focuses more on the exact mechanism behind the observed effects, because such information would facilitate the production of nanoparticles with increased biocompatibility.
T‐cell Tolerance to the Developing Equine Conceptus
Authors: Antczak DF
Published: July 2012

Contents

One of the most intriguing and dramatic examples of immunological tolerance is displayed by the mammalian foetal–placental unit, which thrives as a semi‐allograft in the mother’s uterus during pregnancy. The success of the so‐called foetal allograft stands in stark contrast to the failure of most tissue and organ grafts to survive without genetic matching of donor and recipient or drastic immunosuppression of the recipient’s immune system. Experiments conducted over the past 60 years have revealed multiple mechanisms that enable the conceptus to avoid immunological detection or destruction. Many of these mechanisms are directed towards evading immune‐mediated damage by maternal T lymphocytes, and they can be grouped into three classes: (i) downregulation of major histocompatibility complex (MHC) gene expression in placental trophoblast cells; (ii) local and systemic alterations in maternal immune reactivity; and (iii) innate defence mechanisms of the trophoblast cells that comprise the barrier between foetal and maternal tissues. The redundancy in these protective mechanisms helps ensure the transmission of life from generation to generation and provides a rich field of study of ways in which functional immunological tolerance can be manifest. The variation in placental forms and function among mammalian species present opportunities to discover and understand novel tolerogenic mechanisms that may have broad application in biology, medicine and animal husbandry. This review focuses on the evidence obtained from studies of pregnancy in the mare that support the case for selective T‐cell tolerance to the mammalian conceptus.
An Amazing 10 Years: The Discovery of Egg and Sperm in the 17th Century
Authors: Cobb M
Published: July 2012

Contents

The scientific identification of the key components of sexual reproduction – eggs and sperm – took place during an amazing decade of discovery in the 1660s and 1670s. The names of many of the people involved are now forgotten, and yet their work, and the difficulties they faced and the conflicts they endured, resonate strongly to the present day. Despite this period of innovation, the respective roles of egg and sperm remained unclear for another 170 years. Why did this take so long? And what did people think before these discoveries? By tracing the contours of this major milestone in human knowledge, we can also gain insight into our current knowledge, and the boundaries we may be unwittingly trapped by.
How prepared are rural and remote health care practitioners to provide evidence‐based management for people with chronic lung disease?
Authors: Johnston Catherine Louise , Maxwell Lyndal Jane , Maguire Graeme Paul , Alison Jennifer Ailsey
Published: July 2012

Objective:  To investigate the existing experience, training, confidence and knowledge of rural/remote health care practitioners in providing management for people with chronic obstructive pulmonary disease (COPD).

Design:  Descriptive cross‐sectional, observational survey design using a written anonymous questionnaire. This study formed part of a larger project evaluating the impact of breathe easy walk easy (BEWE), an interactive education and training program for rural and remote health care practitioners.

Setting:  Rural (n = 1, New South Wales) and remote (n = 1, Northern Territory) Australian health care services.

Participants:  Health care practitioners who registered to attend the BEWE training program (n = 31).

Main outcome measures:  Participant attitudes, objective knowledge and self‐rated experience, training and confidence related to providing components of management for people with COPD.

Results:  Participants were from a variety of professional backgrounds (medical, nursing, allied health) but were predominantly nurses (n = 13) or physiotherapists (n = 9). Most participants reported that they had minimal or no experience or training in providing components of management for people with COPD. Confidence was also commonly rated by participants as low. Mean knowledge score (number of correct answers out of 19) was 8.5 (SD = 4.5). Questions relating to disease pathophysiology and diagnosis had higher correct response rates than those relating more specifically to pulmonary rehabilitation.

Conclusion:  The results of this study indicate that some rural and remote health care practitioners have low levels of experience, knowledge and confidence related to providing components of management for people with COPD and that education and training with an emphasis on pulmonary rehabilitation would be beneficial.
Survey on breastfeeding among Chinese female physicians and nurses
Authors: Ouyang Yan‐qiong , Xu You‐xian , Zhang Qing
Published: July 2012

The present study investigated knowledge of and beliefs about breastfeeding among Chinese female physicians and nurses and their breastfeeding practices. This study documented knowledge, attitudes and practices of breastfeeding among Chinese medical staff. A total of 367 female physicians and nurses completed a self‐administered, anonymous questionnaire; 96.2% indicated that breastfeeding was natural, but 29.2% thought it difficult. Only 18.5% of the participants questioned breastfeeding women on feeding status, and 12.8% gave breastfeeding advice when asked. After graduation from school, 79.3% of the participants stated that they did not receive training in breastfeeding. In personal practice, 69.2% initiated breastfeeding; 19.1% were still breastfeeding at 4 months, and only three nurses continued breastfeeding for more than 1 year. In conclusion, breastfeeding‐related knowledge is surprisingly poor, and attitudes are less positive. The exclusive breastfeeding rate was found to be low among Chinese female physicians and nurses. The findings highlight the need to re‐educate medical staff on breastfeeding, and imply the need for Baby‐Friendly Hospital Initiative implementation/training.
Recent insights into the diversity, frequency and ecological roles of phenazines in fluorescent Pseudomonas spp.
Authors: Mavrodi Dmitri V. , Parejko James A. , Mavrodi Olga V. , Kwak Youn‐Sig , Weller David M. , Blankenfeldt Wulf , Thomashow Linda S.
Published: July 2012

Phenazine compounds represent a large class of bacterial metabolites that are produced by some fluorescent Pseudomonas spp. and a few other bacterial genera. Phenazines were first noted in the scientific literature over 100 years ago, but for a long time were considered to be pigments of uncertain function. Following evidence that phenazines act as virulence factors in the opportunistic human and animal pathogen Pseudomonas aeruginosa and are actively involved in the suppression of plant pathogens, interest in these compounds has broadened to include investigations of their genetics, biosynthesis, activity as electron shuttles, and contribution to the ecology and physiology of the cells that produce them. This minireview highlights some recent and exciting insights into the diversity, frequency and ecological roles of phenazines produced by fluorescent Pseudomonas spp.
Mn‐catalase (Alr0998) protects the photosynthetic, nitrogen‐fixing cyanobacterium Anabaena PCC7120 from oxidative stress
Authors: Banerjee Manisha , Ballal Anand , Apte Shree Kumar
Published: July 2012

Role of the non‐haem, manganese catalase (Mn‐catalase) in oxidative stress tolerance is unknown in cyanobacteria. The ORF alr0998 from the Anabaena PCC7120, which encodes a putative Mn‐catalase, was constitutively overexpressed in Anabaena PCC7120 to generate a recombinant strain, AnKat+. The Alr0998 protein could be immunodetected in AnKat+ cells and zymographic analysis showed a distinct thermostable catalase activity in the cytosol of AnKat+ cells but not in the wild‐type Anabaena PCC7120. The observed catalase activity was insensitive to inhibition by azide indicating that Alr0998 protein is indeed a Mn‐catalase. In response to oxidative stress, the AnKat+ showed reduced levels of intracellular ROS which was also corroborated by decreased production of an oxidative stress‐inducible 2‐Cys‐Prx protein. Treatment of wild‐type Anabaena PCC7120 with H2O2 caused (i) RNA degradation in vivo, (ii) severe reduction of photosynthetic pigments and CO2 fixation, (iii) fragmentation and lysis of filaments and (iv) loss of viability. In contrast, the AnKat+ strain was protected from all the aforesaid deleterious effect under oxidative stress. This is the first report on protection of an organism from oxidative stress by overexpression of a Mn‐catalase.