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Cryopreservation-induced proteomic alterations in Pêga donkey (Equus asinus) spermatozoa.

Semen cryopreservation is a key tool for assisted reproduction and genetic conservation, but its efficiency remains limited in donkeys, compromising post-thaw sperm quality. This study aimed to characterize the proteomic profile of Pêga donkey spermatozoa and to investigate molecular mechanisms associated with cryopreservation-induced impairment of sperm function. Semen samples were collected from Pêga jacks and evaluated for sperm motility and vigor before and after cryopreservation. Quantitative proteomic analysis was performed by LC-MS/MS, followed by bioinformatic characterization of differentially abundant proteins. Cryopreservation markedly reduced sperm motility in all animals, whereas sperm vigor showed only a non-significant tendency toward reduction, suggesting sublethal cryoinjury primarily affecting flagellar efficiency. Proteomic profiling identified 554 proteins, of which 98 were differentially abundant between in natura and cryopreserved spermatozoa. Functional enrichment analyses showed that these proteins were mainly associated with energy metabolism, mitochondrial oxidative phosphorylation, glycolysis, cytoskeletal organization, signal transduction, proteostasis, and oxidative stress response. Notably, proteins involved in ATP production, mitochondrial function, and axonemal organization were significantly altered, supporting a mechanistic link between metabolic dysfunction, flagellar structural disorganization, and reduced post-thaw motility. Overall, cryopreservation induced coordinated and compartment-specific remodeling of the donkey sperm proteome, particularly affecting pathways essential for motility and functional competence. These findings provide new molecular insights into the cryobiological vulnerability of donkey spermatozoa and establish a mechanistic basis for the development of more effective, biology-driven cryopreservation strategies for this species.

Animals↗

The importance of ignorance.

The need for people to keep their genetic data confidential is crucial to help exploit medical advances, a key British Committee believes. Nigel Williams reports.

Databases, Genetic↗

Evolutionary genetics: choosing to evolve.

The evolution of mate choice is believed to be important in speciation. A recent experiment involving mating preference evolution in laboratory yeast populations supports theoretical predictions that this can occur without complete genetic isolation between populations, strengthening the case that ecological specialization as well as physical separation can lead to speciation.

Genetic Speciation↗

Comparative aspects of zebrafish (Danio rerio) as a model for aging research.

The zebrafish has emerged over the past decade as a major model system for the study of development due to its invertebrate-like advantages coupled with its vertebrate biology. These features also make it a potentially valuable organism for gerontological research. The main advantages of zebrafish include its economical husbandry, small yet accessible size, high reproductive capacity, genetic tractability, and a large and growing biological database. Although zebrafish life span is longer than rodents, it shares the feasibility of large-scale mutational analysis with the extremely short-lived invertebrate models. This review compares zebrafish with the more widely used model organisms used for aging research, including yeast, worms, flies, mice, and humans.

Aging↗

Infanticide and infant defence by males--modelling the conditions in primate multi-male groups.

Infanticide by primate males was considered rare if groups contain more than one adult male because, owing to lower paternity certainty, a male should be less likely to benefit from infanticide. Guided by recent evidence for strong variation of infanticide in primate multi-male groups, we modelled the conditions for when infanticide should occur for a group with a resident and an immigrant male. Setting the parameters (e.g. infant mortality, reduction of interbirth interval, life-time reproductive success, genetic representation) to fit the conditions most commonly found in nature, we develop a game-theoretic model to explore the influence of age and dominance on the occurrence of infanticide and infant defence. Male age strongly impacts the likelihood of an attack which is modified by the father's defence. If the new male is dominant he is likely to attack under most circumstances whereas a subordinate male will only attack if the father does not defend. These model scenarios fit the conditions under which infanticide is known to occur in primate multi-male groups and offer an explanation why infanticide is common in some multi-male groups and rare in others. Overall, the benefits for infanticidal males are strongly governed by a reduced interbirth interval while advantages via improved genetic representation in the gene pool contribute but a minor fraction.

Animals↗

Identification of risk factors for prevention and early diagnosis of a-symptomatic post-menopausal women.

At present, healthcare for post-menopausal a-symptomatic women offers a great opportunity to identify risk factors (RFs) for prevention of diseases which cause high mortality or disability. It is always necessary to promote a healthy lifestyle and identify RFs in order to stratify people according their risk of suffering cardiovascular disease (CVD), cancer (especially of the lung, breast and colon) and osteoporosis. Cardiovascular disease is the leading cause of death. The main independent factors are: age, smoking, high blood pressure, elevated LDL, low HDL cholesterol, and diabetes. Several global risk scores, such as the Framingham score, allow us to assess the risk of suffering a fatal or severe accident in the next 10 years. According to such scores, patients are classified as high, intermediate or low-risk and several intervention strategies may be proposed. There are several genetic and reproductive factors related to breast cancer. Global risk can be assessed by means of the Gail index, which predicts both individual lifetime and 5-year risk. This allows us to recommend breast cancer chemoprevention in high-risk patients. Age, family history, previous fragility fractures, low body mass index, smoking and the administration of oral glucocorticoids are the main osteoporosis RFs. Their assessment allows the indication of bone mineral density (BMD) testing and, according to the T-score, whether to start anti-resorptive therapy. The common problem with RFs is their variability among different populations and fact that the extrapolation of data for an individual is difficult.

Breast Neoplasms↗

Fatty acids from seeds of Pinus pinea L.: composition and population profiling.

Pinus pinea L. is widely disseminated all over the Mediterranean Basin. Qualitatively, P. pinea fatty acid seed composition is identical and typical of the genus Pinus. This composition is made of unsaturated oil with several unusual polymethylene-interrupted unsaturated fatty acids. Linoleic acid is the major fatty acid followed by oleic, palmitic and stearic acids. Quantitatively, for all Mediterranean populations, total amounts of fatty acids seem to be fairly constant and independent from their origin. When applying principal component analysis, it seems that there is not a distinct geographical variability. Tunisian populations appear to be integral part of the Mediterranean populations without any particular structuring. Taking into account this research and the data reported in the literature, we can confirm that P. pinea expresses no significant variability. This low genetic diversity revealed by fatty acid composition can be explained by anthropogenetic diffusion of genetically homogeneous reproductive material as early as the first explorations.

Fatty Acids↗

Contraception in felids.

Contraceptives are used for reversible reproductive control in genetically valuable wild felids, as permanent reproductive control in generic wild felids, and as an economically practicable means to control feral cats. The progestin contraceptives, megestrol acetate, melengesterol acetate, medroxyprogesterone acetate, and levonorgestrol (administered orally, in implants, or as depot injections), are effective in preventing pregnancy. However, long-term use is associated with endometrial hyperplasia, endometrial cancer, and mammary cancer. Gonadotropin releasing hormone analogs or luteinizing hormone vaccines that achieve contraception by suppressing ovarian or testicular function, do not have the adverse health effects of progestins. However, reliable reversibility has not been demonstrated, and male secondary sex characteristics may be suppressed. Bisdiamines also inhibit spermatogenesis and lower circulating testosterone concentrations in treated male cats. Porcine zona pellucida vaccines are ineffective contraceptives in felids and may cause serious health problems when combined with some adjuvants. Because of the limited availability of non-progestin contraceptives and side effects associated with some agents, widespread application of contraception to felids has been curtailed. More non-steroidal methods of contraception should be tested in the future to provide alternatives for controlling reproduction in felids. Furthermore, all empirical information on contraceptive safety and efficacy should be assembled in a database to provide the knowledge needed by veterinarians and managers to determine benefits/risks of currently available contraceptives in felids, both domestic and wild.

Animals↗

Repression of hspA2 messenger RNA in human testes with abnormal spermatogenesis.

OBJECTIVE: To evaluate the messenger RNA (mRNA) expression of hspA2 in testes of infertile men with azoospermia. DESIGN: Prospective study. SETTING: Center for Reproduction and Genetics, Pundang Je-Saeng General Hospital, Dae-Jin Medical Center, Korea. PATIENT(S): Azoospermic patients (n = 15) undergoing testicular biopsy for pathologic evaluation were selected. INTERVENTION(S): After pathologic evaluation, testicular biopsy specimens were subdivided into three groups: group 1, normal spermatogenesis (n = 5); group 2, spermatocyte arrest (n = 5); and group 3, Sertoli cell-only syndrome (n = 5). The levels of hspA2 mRNA expression were compared in testes of group 1, group 2, and group 3 with the use of a competitive reverse transcription polymerase chain reaction (RT-PCR) technique. MAIN OUTCOME MEASURE(S): Comparison of hspA2 mRNA levels in testes. RESULT(S): On competitive RT-PCR analyses for hspA2 mRNA, significant hspA2 expression was observed in group 1, whereas a very low level of hspA2 was expressed in groups 2 and 3. CONCLUSION(S): This study demonstrates that hspA2 gene expression is down-regulated in human testes with abnormal spermatogenesis, which in turn suggests that the hspA2 gene might play a specific role during meiosis in human testes.

Cell Cycle↗

Human immunodeficiency virus and assisted reproduction: reconsidering evidence, reframing ethics.

OBJECTIVE: To review the advances in the treatment of human immunodeficiency virus (HIV) infection and revisit the medical, ethical, and legal issues surrounding infertility management in HIV-infected couples. DESIGN: Analytic review. RESULTS(S): HIV infection continues to be a serious public health and reproductive issue. However, present policies which allow for the categorical exclusion of HIV-infected individuals from infertility services should be reconsidered in light of improvements in the prognosis of infected individuals and a dramatic decrease in the risk of vertical transmission. An analysis of the ethical cogency of the arguments against the provision of services does not substantiate the exclusion of HIV-infected individuals; rather, the principle of justice requires that HIV-infected women be treated the same way as a woman who might have an increased risk of conceiving a child with a disability or a may have a decreased life expectancy due to a chronic illness such as diabetes. Ethical disagreement notwithstanding, with the precedents recently established by the Americans with Disabilities Act (ADA), discrimination based on HIV status would also likely be unlawful under most circumstances. CONCLUSIONS(S): With advances in the treatment of HIV infection, contextualized counseling and a respect for patients' decisions regarding infertility treatment should be adopted as public policy. It is neither ethically nor legally justifiable to categorically exclude individuals from infertility services on the basis of HIV infection.

Acquired Immunodeficiency Syndrome↗