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High-altitude environments present formidable challenges for survival and reproduction, with organisms facing limited oxygen availability and scarce nutrient resources. The yak (Bos grunniens), indigenous to the Tibetan Plateau, has notably adapted to these extreme conditions. This study delves into the genomic basis of the yak's adaptation, focusing on the positive selection acting on genes involved in nutrient assimilation pathways. Employing techniques in comparative genomics and molecular evolutionary analyses, we selected genes in the yak that show signs of positive selection associated with nutrient metabolism, absorption, and transport. Our findings reveal specific genetic adaptations related to nutrient metabolism in harsh climatic conditions. Notably, genes involved in energy metabolism, oxygen transport, and thermoregulation exhibited signs of positive selection, suggesting their crucial role in the yak's successful colonization of high-altitude regions. The study also sheds light on the yak's immune system adaptations, emphasizing genes involved in response to various stresses prevalent at elevated altitudes. Insights into the yak's genomic makeup provide valuable information for understanding the broader implications of high-altitude adaptations in mammalian evolution. They may contribute to efforts in enhancing livestock resilience to environmental challenges.
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Altitud , Genoma , Animales , Bovinos , Genómica , Evolución Molecular , Oxígeno , MamíferosRESUMEN
Male fertility is affected by multiple endogenous stressors, including reactive oxygen species (ROS), which greatly deteriorate the fertility. However, physiological levels of ROS are required by sperm for the proper accomplishment of different cellular functions including proliferation, maturation, capacitation, acrosomal reaction, and fertilization. Excessive ROS production creates an imbalance between ROS production and neutralization resulting in oxidative stress (OS). OS causes male infertility by impairing sperm functions including reduced motility, deoxyribonucleic acid damage, morphological defects, and enhanced apoptosis. Several in-vivo and in-vitro studies have reported improvement in quality-related parameters of sperm following the use of different natural and synthetic antioxidants. In this review, we focus on the causes of OS, ROS production sources, mechanisms responsible for sperm damage, and the role of antioxidants in preserving sperm fertility.
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Antifreeze proteins are biologically active substances which protect living organisms against freezing injuries. The effect of a synthetic antifreeze protein carboxylated poly l-lysine (CPLL) in the extender was evaluated in the presence of a conventional cryoprotective agent, dimethyl sulfoxide (Me2SO), for freezing rabbit sperm cells. The experiment was conducted according to 2 × 3 factorial design including two Me2SO (5 or 8%) and three CPLL (0, 0.5 or 1%) concentrations. CPLL supplementation improved post-thaw live and live-acrosome intact sperm rates (P<0.01) without a prominent influence on the motility (P>0.05) and live-membrane intact (P>0.05) sperm rates. The most striking effect of CPLL supplementation was seen on the DNA integrity where it reduced DNA fragmentation of sperm cells significantly by interacting Me2SO (P < 0.01) during freezing and thawing. However, it could not replace Me2SO in the extender and did not improve pregnancy rate. In conclusion, CPLL supplementation to the extender in the presence of Me2SO improved sperm quality parameters and post-thaw DNA integrity.
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Dimetilsulfóxido , Preservación de Semen , Animales , Criopreservación/métodos , Crioprotectores/farmacología , Dimetilsulfóxido/farmacología , Femenino , Fertilidad , Masculino , Polilisina/farmacología , Embarazo , Conejos , Preservación de Semen/veterinaria , Motilidad Espermática , EspermatozoidesRESUMEN
Laparoscopic artificial insemination technique (LAI) is described to overcome reduced fertility problems in sheep artificial insemination (AI) programmes with frozen semen. Later on, this technology was modified for endangered non-domestic cats to deposit low quality or reduced number of sperm cells hardly obtained by electro-ejaculation into the oviduct. This technique by passes the complex structure of cervix and efficiently transfers the sperm cells to the point of fertilization. In recent years, rabbits are becoming popular transgenic animal models producing various therapeutic and commercial products, as well as being experimental animals for disease models. The worldwide transportation of frozen semen and re-establishment of transgenic lines using AI technology has become a common practice. Therefore, this study was designed to describe a laparoscopic intrauterine insemination technique, which might assist in conceiving the animals with limited number of sperm cells. The female rabbits were laparoscopically (n = 22) or vaginally (n = 13) inseminated with frozen-thawed semen samples containing approximately 10 × 106 motile sperm. The laparoscopic insemination technique provided higher pregnancy rate (45.5%) than vaginal insemination technique (7.7%) (p < .05). In conclusion, the described laparoscopic AI might be a new alternative technique, thus enabling limited or low-quality frozen sperm samples to establish pregnancy in rabbits.
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Inseminación Artificial/veterinaria , Laparoscopía/veterinaria , Conejos , Animales , Criopreservación/veterinaria , Femenino , Fertilidad , Inseminación Artificial/métodos , Laparoscopía/métodos , Masculino , Embarazo , Índice de Embarazo , Preservación de Semen/veterinariaRESUMEN
Assessment of male fertility is based on the evaluation of sperm. Semen evaluation measures various sperm quality parameters as fertility indicators. However, semen evaluation has limitations, and it requires the advancement and application of strict quality control methods to interpret the results. This article reviews the recent advances in evaluating various sperm-specific quality characteristics and methodologies, with the help of different assays to assess sperm-fertility status. Sperm evaluation methods that include conventional microscopic methods, computer-assisted sperm analyzers (CASA), and flow cytometric analysis, provide precise information related to sperm morphology and function. Moreover, profiling fertility-related biomarkers in sperm or seminal plasma can be helpful in predicting fertility. Identification of different sperm proteins and diagnosis of DNA damage has positively contributed to the existing pool of knowledge about sperm physiology and molecular anomalies associated with different infertility issues in males. Advances in methods and sperm-specific evaluation has subsequently resulted in a better understanding of sperm biology that has improved the diagnosis and clinical management of male factor infertility. Accurate sperm evaluation is of paramount importance in the application of artificial insemination and assisted reproductive technology. However, no single test can precisely determine fertility; the selection of an appropriate test or a set of tests and parameters is required to accurately determine the fertility of specific animal species. Therefore, a need to further calibrate the CASA and advance the gene expression tests is recommended for faster and field-level applications.
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Effect of sericin pretreatment of sperm cells on the osmotic tolerance, ability to undergo acrosome reaction induced by calcium ionophore (CI), heparin (H) or lysophosphatidylcholine (LPC), post-thaw sperm quality and in vivo fertility was evaluated in four successive experiments in rabbit. In experiment 1, fresh semen was pretreated with sericin (0, 0.1% or 0.5% w/v) before exposing to fructose solutions adjusted to either 50, 100, 290, 500 or 1000 mOsm/L. Sericin pretreatment increased sperm livability in addition to live-membrane intact and total membrane intact sperm rates (Pâ¯<â¯0.05) in 50 and 290 mOsm/L groups. In experiment 2, sperm samples were pretreated by either 0.1 or 0.5% sericin after removal of the semen plasma. CI, H or LPC were used to induce acrosome reaction in pretreated sperm samples. Sericin pretreatment, reduced the ability of sperm cells to undergo acrosome reaction (Pâ¯<â¯0.05) in vitro. In experiment 3, ejaculates were frozen with or without sericin pretreatment in DMSO-sucrose extender. In post-thaw samples sericin pretreatment improved total and progressive motility, livability, membrane and acrosome integrity in a dose dependent manner (Pâ¯<â¯0.05). In vivo fertility trials by artificial inseminations revealed contradictory results in experiment 4. Although 0.5% sericin pretreatment totally inhibited fertility, 0.1% sericin provided high pregnancy rates. In conclusion; sericin pretreatment enhances osmotic tolerance and post-thaw sperm quality, but reduces the ability of rabbit sperm cells to undergo in vitro induced acrosome reaction, but this effect is restored in vivo by dose dependent manner.
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Reacción Acrosómica/efectos de los fármacos , Criopreservación/métodos , Crioprotectores/farmacología , Preservación de Semen/métodos , Sericinas/farmacología , Motilidad Espermática/efectos de los fármacos , Acrosoma/efectos de los fármacos , Animales , Femenino , Fertilidad , Congelación , Inseminación Artificial/métodos , Masculino , Embarazo , Conejos , Semen/efectos de los fármacos , Análisis de Semen , Espermatozoides/efectos de los fármacosRESUMEN
Stock theft is an endemic crime particularly affecting deep rural areas of Pakistan. Analysis of a series of cases was conducted to describe features of herds and farmers who have been the victims of cattle and/buffalo theft in various villages of Punjab in Pakistan during the year 2012. A structured interview was administered to a sample of fifty three affected farmers. The following were the important findings: i) incidents of theft were more amongst small scale farmers, ii) the rate of repeat victimization was high, iii) stealing was the most common modus operandi, iv) the majority of animals were adult, having high sale values, v) more cases occurred during nights with crescent moon, vi) only a proportion of victims stated to have the incident reported to the police, vii) many farmers had a history of making compensation agreements with thieves, viii) foot tracking failed in the majority of the cases, ix) all the respondents were willing to invest in radio frequency identification devices and advocated revision of existing laws. The study has implications for policy makers and proposes a relationship between crime science and veterinary medicine.