Sex Of Animals Research Articles

DO HEALTHY COQUEREL'S SIFAKAS IN CAPTIVITY HAVE UNUSUALLY LOW CIRCULATING CORTISOL?

Cortisol, and other glucocorticoids, are routinely used as markers of physiological stress in wildlife. Typically, stress activates the hypothalamic-pituitary-adrenal (HPA) axis, with adrenocorticotropic hormone (ACTH) signaling the adrenal glands to release cortisol. Nevertheless, recent anecdotes in captive Coquerel's sifakas (Propithecus coquereli), strepsirrhine primates that are difficult to maintain under human care, may challenge the assumption that physiological stress universally increases circulating cortisol. Here, the authors ask if low circulating cortisol and minimal response to adrenal stimulation might be hallmarks of outwardly healthy sifakas in captivity. Comparative ACTH stimulation or control tests were performed in 10 Coquerel's sifakas and six ring-tailed lemurs (Lemur catta) at the Duke Lemur Center (DLC). At baseline, sifakas had average cortisol concentrations of just 0.67 µg/dl, whereas those of ring-tailed lemurs averaged 12.53 µg/dl. Stressful pre-experiment procedures, including kenneling and handling, activated the HPA axis in ring-tailed lemurs, masking further cortisol release from ACTH administration; however, neither these procedures nor exogenous ACTH raised cortisol concentrations in sifakas. Additionally, cortisol in dozens of serum samples from DLC sifakas banked over 17 yr was assayed. Across samples, cortisol concentrations averaged just 0.49 µg/dl and did not vary by animal sex, age, or housing condition. Comparable samples from two individual sifakas in sepsis at the end of life (4.28 and 21.88 µg/dl) indicate that the assay does capture meaningful variation in cortisol in captive sifakas, although robust biological validation is needed. Currently there is a lack of comparative data from wild Coquerel's sifakas that might determine if these unusual endocrine patterns are characteristic of the species or a function of captivity. If the latter, chronic stress in captivity could lead to a downregulated HPA axis, with persistent hypocortisolism perhaps contributing to the Coquerel's sifaka's susceptibility to infection under human management.

Protocol for the systematic review of age and sex in preclinical models of age-correlated diseases

The translation of animal-based biomedical research into clinical research is often inadequate. Maximizing translation should be central to animal research on human diseases, guiding researchers in study design and animal model selection. However, practical considerations often drive the choice of animal model, which may not always reflect key patient characteristics, such as sex and age, impacting the disease's course. Despite diseases affecting both sexes, researchers frequently use male mice. To address this imbalance, journals and funding agencies have begun questioning the sex of animals used in studies and issued new guidelines. Conversely, the age of rodents is rarely discussed, even though many diseases primarily affect older patients. Young mice are commonly used, even in studies of diseases affecting older adults. Systematic comparisons between the age of rodents used and the age of patients in clinical trials are lacking. In this review, we systematically analyze the age and sex of mice used to model the five leading causes of global disability-adjusted life-years over the age of 75. We compare the results with the age and sex of patients in clinical trials focusing on Alzheimer's disease, stroke, type 2 diabetes mellitus, ischemic heart disease, and chronic obstructive pulmonary disease. We also analyze whether the age of the mice used has changed over the past decade. By systematically assessing the age and sex of the mice, we aim to initiate a discussion on the appropriate choice of animal model to improve the translatability of research results.

Diet and Body Weight Dynamics in the Spotted Seal, <i>Phoca largha</i> (Pallas, 1811), Kept in Sea Pens

Nutritious diet is one of the most important factors in the successful management of captive animals. Basic methods for selecting diets for marine mammals have been described in the literature, yet methods developed for certain marine mammal species kept under specific conditions are quite rare. The diets of three male and two female spotted seals, Phoca largha Pallas, 1811, kept in sea pens at the Primorsky Aquarium, Branch of the NSCMB FEB RAS (Vladivostok, Russia), are discussed in the article. The diets have been formulated based on the natural biological processes of this species in the wild. Information on them has been obtained from our own observations and from literature sources. Based on individual needs, adjustments have been made to the diets of the spotted seals, including pregnant and lactating females. The main food items of the spotted seal were Pacific herring, Clupea pallasii, Atka mackerel, Pleurogrammus monopterygius, commander squid, Berryteuthis magister, pink salmon, Oncorhynchus gorbuscha, chum salmon, Oncorhynchus keta, char, Salvelinus sp., capelin, Mallotus villosus, and shrimp, Pandalus sp. It has been found that the physiological condition of the animals (molting, reproductive status, sex, and age) directly influences the qualitative and quantitative parameters of food intake. The diet and body weight of the spotted seals were significantly influenced by seasonal changes (water and air temperature and natural biological rhythms). The obtained data can be used for selection of optimal feeding of P. largha.

Cephalopod Sex Determination and its Ancient Evolutionary Origin.

Octopuses, squids, and cuttlefishes - the coleoid cephalopods - are a remarkable branch in the tree of life whose members exhibit a repertoire of sophisticated behaviors (Hanlon and Messenger, 2018). As a clade, coleoids harbor an incredible variety of novel traits including the most complex nervous system among invertebrates, derived camera-type eyes, and rapid adaptive camouflage abilities (Young, 1971; Hanlon, 2007). The burst of evolutionary novelty that distinguishes cephalopods is even more striking in a phylogenetic context; cephalopods are a deeply diverged lineage that last share a common ancestor with other extant molluscs in the Cambrian period, roughly 550 million years ago (Ponder and Lindberg, 2008; Huang et al., 2022). With recent advances in genome sequencing technologies, we have the capability to explore the genomic foundations of cephalopod novelties. Here, using PacBio long-read sequencing of genomic DNA and IsoSeq full-length mRNA sequencing, we provide a novel chromosome-scale reference genome and annotation for a female California two-spot octopus ( O. bimaculoides ). Our assembly reveals that the female octopus has just one sex chromosome, consistent with a ZO karyotype, while the male has two (ZZ), providing the first evidence of genetic sex determination in cephalopods. We use our assembly and annotation in combination with existing genomic information from other cephalopods to create the first whole genome alignments from this group and demonstrate that the sex chromosome is of an ancient origin, before the radiation of extant cephalopods approximately 480 million years ago (Huang et al., 2022), and has been conserved to the present day in all cephalopod genomes available.

Estimation of genetic parameters for racing time and ranking in Thoroughbred horses

This study aimed to estimate genetic parameters for race time in seconds and final ranking, as well as to analyze the genetic trends associated with race time. The study utilized a dataset consisting of 23,290 records of race times and final ranks at distances of 1,000, 1,600, and 2,000 m from 6,213 Thoroughbred horses from the São Paulo Jockey Club. Our model considered the year of the run, animal sex, race class, track conditions, the linear effect of horse weight and age, and the quadratic effect of age as fixed covariates. Random effects included direct additive genetic, animal permanent environmental, and residual effects. Heritability estimates ranged from 0.01±0.03 to 0.17±0.04 (race time); 0.04±0.03 to 0.09±0.04 (final ranking), and repeatability from 0.19±0.02 to 0.37±0.02 (race time) and 0.15±0.02 to 0.23±0.04 (final ranking). Pearson's correlations of estimated breeding values between race time and ranking ranged from -0,027±0.16 to 0.84±0.01. When analyzing the genetic trend for races at a distance of 1,000 m, we observed a decrease in race time over time. However, for races at 1,600 and 2,000 m, a clear pattern of time reduction was not apparent. Race time offers a more promising response to selection, particularly in shorter races. Selecting for race time is expected to have a greater indirect impact on final rank. Genetic trends have revealed limited genetic progress over the years; therefore, it is advisable to reevaluate the current selection process.

Zoographics in the Journal of the Experimental Analysis of Behavior: Increasing inclusion of female animals.

We examined the zoographics, or the characteristics of nonhuman animal subjects, reported for the entirety of the Journal of the Experimental Analysis of Behavior (JEAB) through the most recent complete year (1958-2023). Animal sex in particular was evaluated to determine whether the lack of inclusion of female subjects in other disciplines extends to JEAB. Through systematic coding of all nonhuman empirical articles, we found consistent underreporting of most zoographics and a disproportionate use of male subjects relative to female subjects. Additionally, animal sex was commonly unreported and the inclusion of both male and female subjects was sparse. Recent years show some improvement, but greater inclusion is required. Lack of female subjects in research as well as underreporting of zoographics can generate unrepresentative results and hamper replication, generalization, and translation. We provide resources to guide future research and reporting suggestions such as equal inclusion and disaggregation of data by sex. We also clarify misunderstandings about the use of both sexes in research such as beliefs that it necessarily increases the cost of research.

Molecular and serological diagnosis of the circulating Trypanosoma evansi in Egyptian livestock with risk factors assessment

This study aimed to characterize and determine the prevalence and the associated risk factors of trypanosomiasis in different Egyptian livestock from various governorates using molecular and serological techniques, adding to an assessment of some biochemical alterations in serum samples. A total 1019 blood samples were collected from nine governorates in the period from January 2020 to September 2021 from cattle (n = 752), buffaloes (n = 42), sheep (n = 65), goats (n = 60), donkeys (n = 54), and horses (n = 46). Molecular investigation followed by sequencing confirmed the presence of only Trypanosoma evansi (T. evansi) infection with a prevalence rate of 3.73 % (38/1019). Serologically, T. evansi was detected by indirect ELISA in 11 samples out of 519 negative PCR ones, with an overall prevalence 2.1 %. Furthermore, statistical difference was found between investigated governorates in both molecular and seroprevalence. Surprisingly, the risk of T. evansi infection was significantly (P < 0.05) higher in winter (9.83 %) than in autumn (1.4 %), while no infection was recorded in the spring and summer seasons. No significant difference regarding animal hosts, age, and sex as risk factors was recorded. Serum biochemical analysis showed a non-significant decrease of total proteins, albumin, A/G ratio, and HDL-cholesterol in cattle, equine, and goats with a non-significant increase in total globulins level. In sheep, a significant increase was determined in all tested parameters except a significant decrease in the level of albumin and A/G ratio. To the best of our knowledge, this is the first large-scale epidemiological study determining the endemicity of the neglected T. evansi infection in different animal species in multiple governorates of Egypt. It is recommended to use both molecular and serological techniques for efficient diagnosis of trypanosomiasis as a preliminary approach to control the disease.

Exposure patterns and the risk factors of Crimean Congo hemorrhagic fever virus amongst humans, livestock and selected wild animals at the human/livestock/wildlife interface in Isiolo County, upper eastern Kenya.

Crimean Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease caused by CCHF virus (CCHFV). The disease has a complex transmission cycle that involves a wide range of hosts including mammalian and some species of birds. We implemented a sero-epidemiological study in Isiolo County, Kenya, to determine relative seroprevalences of CCHFV in humans, livestock and in wild animals. In addition, we identified subject and environment level factors that could promote exposure to CCHFV. Humans (n = 580) and livestock (n = 2,137) were recruited into the study through a multistage random sampling technique, and in addition, various species of wild animals (n = 87) were also sampled conveniently. Serum samples from all recruited humans and animals were collected and screened for CCHFV antibodies using ID Screen multispecies, double-antigen IgG enzyme-linked immunosorbent assay (ELISA). The overall anti-CCHFV IgG seroprevalences in humans, cattle, goats, sheep and camels were 7.2% [95% CI: 3.1-15.8%], 53.9% [95% CI: 30.7-50.9%], 11.6% [95% CI: 7.2-22.5%], 8.6% [95% CI: 3-14%] and 89.7% [95% CI: 78-94%], respectively. On average, the sampled wild animals had CCHFV seroprevalence of 41.0% [95% CI: 29.1-49.4%]; giraffes had the highest mean CCHF seroprevalence followed by buffaloes, while impala had very low exposure levels. Statistical analyses using mixed effects logistic regression models showed that CCHFV exposure in humans was significantly associated with male gender, being over 30 years of age and belonging to a household with a seropositive herd. In livestock, a combination of animal- and environment level factors including older animals, being in an area with high normalized difference vegetation index (NDVI) and high vapour pressure deficit were significantly associated with CCHFV infection. Age, sex and species of wild animals were considered as the key risk factors in the analysis, but none of these variables was significant (P-value = 0.891, 0.401 and 0.664, respectively). Additionally, RT-qPCR analysis revealed the presence of CCHFV RNA in camels (30%), cattle (14.3%), and goats (3.8%), but not in humans, sheep, or wild animals. This study demonstrates that environmental factors, such as NDVI and vapor pressure deficit, affect CCHFV exposure in livestock, while the presence of infected livestock is the key determinant of human exposure at the household level. These findings underscore the importance of using One Health approaches to control the disease in human-livestock-wildlife interfaces. For instance, the existing CCHF surveillance measures could be enhanced by incorporating algorithms that simulate disease risk based on the environmental factors identified in the study. Additionally, tick control in livestock, such as the use of acaricides, could reduce CCHFV exposure in livestock and, consequently, in humans.

Bovine Hydatidosis: Prevalence and Economic Implication in Torra Municipality Abattoir, Central Ethiopia Region

Objective: This study aimed to determine the prevalence of hydatid cysts and assess their direct economic impact. Methods: The study utilized a cross-sectional design to examine cattle slaughtered in the Torra Municipal Abattoir, in which 384 bovine species were systematically selected. Results: Out of the 384 slaughtered animals, 66 were found to have bovine hydatid cysts. A total of 112 cysts were collected, 44 (39.29%) of which were viable and 68 (60.71%) calcified. All examined organs showed hydatid cysts, but livers and lungs were most commonly affected, while tongues had the least amount. In terms of viable cysts, lung and liver contained the highest proportions, followed by heart and tongue. Consequently, the lung was the organ that was often impacted and had the greatest number of cysts. It was calculated that US$ 2,909 was lost annually as a direct economic loss. The animal's origin and sex did not significantly affect the infection rate statistically (p greater than 0.05). Similarly, there was no significant difference with age (p greater than 0.05). Conclusions: The study revealed a notable prevalence and economic impact of bovine hydatidosis in the study area. Therefore, it is crucial to implement effective control and preventive measures to mitigate the impact of disease's impact on public health.

Progress on SOX9 and its enhancers in mammalian sex determination.

The sex determination in mammals refers to the development of an initial bipotential organ, termed the bipotential gonad/genital ridge, into either a testis or an ovary at the early stages of embryonic development, under the precise regulation of transcription factors. SOX9 (SRY-box transcription factor 9) is a multifunctional transcription factor in mammalian development and plays a critical role in sex determination and subsequent male reproductive organs development. Recent studies have shown that several enhancers upstream of SOX9 also play an important role in the process of sex determination. In this review, we summarize the progress on the role of SOX9 and its gonadal enhancers in sex determination. This review will facilitate to understand the regulatory mechanism of sex determination of SOX9 and provides a theoretical basis for the further development of animal sex manipulation technologies.

Prevalence and associated risk factors of hydatidosis in cattle slaughtered at Wolaita Sodo municipality abattoir.

Hydatidosis, caused by the larval stage of the tapeworm Echinococcus granulosus, affect cattle by forming hydatid cyst in thier lungs, livers and pose great financial loss in animal production and country's economy by both direct and indirect effect. Despite its great economic and health importance, there is an absence of current information on cystic echinococcosis in cattle slaughtered at Wolaita Sodo municipality abattoir in Ethiopia. Current investigation determines the prevalence, organ distribution and fertility of hydatid cysts in cattle slaughtered at the Wolaita Sodo municipality abattoir in Ethiopia. A cross-sectional study was conducted from February, 2023, to October, 2023, at Wolaita Sodo municipality abattoir in southern Ethiopia, through regular meat examinations and cyst characterisation to determine the prevalence, organ distribution and fertility of hydatid cysts. The overall prevalence of hydatidosis recorede in current study was 17.9% (69/384) and has shown a statistically significant association (p < 0.05) with the body condition of cattle. However, there was no statistically significant association (p > 0.05) between the prevalence of hydatidosis and other risk factors such as sex, breed, production system and origin of animals. This study showed that the lungs and liver were the most affected organs in cattle, followed by the spleen and kidneys. On cyst characterisation, the majority of hydatid cysts were found sterile (55.4%) followed by fertile (38.8%) and calcified (8.7%) cysts. Out of 125 fertile hydatid cysts tested for survival, 18.8% (58/321) were viable and 20% (67/321) were nonviable. The finding of this study shows that cystic echinococcus was important health threat of the cattle and widespread in the internal organs of affected cattle causingsignificant economic loss by condemning edible organs that are not suitable for human consumption. Therefore, urgent and integreted preventive action is needed to disrupt the life cycle of cystic echinococcosis to tackle subsequent financial loss and risk of zoonosis to humans in the study area.

Sexual Dimorphism in the Musculoskeletal System: Sex Hormones and Beyond.

Mounting evidence indicates that whereas some fundamental aspects of bone cell differentiation and function are similar in females and males, there is a clear contribution of sex/gender on the effects of signaling molecules on bone mass and strength and, consequently, on the effects of pharmacologic approaches to treat skeletal disorders. However, until recently, most studies were designed and performed using only 1 sex, resulting in a scarcity of published information on sexual dimorphism of the musculoskeletal system, including the mandible/masticatory muscles and the axial and appendicular bones and skeletal muscles. Further, it is now recognized that scientific rigor requires the study of both males and females. Therefore, there is an increasing need to understand the molecular and cellular basis for the differential outcomes of genetic manipulations and therapeutic agent administration depending on the sex of the experimental animals. Studies have shown higher muscle mass, cancellous bone mass, and long bone width in males compared with females as well as different traits in the pelvis and the skull, which are usually used for gender identification in forensic anthropology. Yet, most reports focus on the role of sex hormones, in particular, the consequences of estrogen deficiency with menopause in humans and in ovariectomized animal models. In addition, emerging data is starting to unveil the effects of gender-affirming hormonal therapy on the musculoskeletal system. We summarize here the current knowledge on the sex/gender-dependent phenotypic characteristics of the bone and skeletal muscles in humans and rodents, highlighting studies in which side by side comparisons were made.

The Glutamine-Glutamate Cycle Contributes to Behavioral Feminization in Female Rats

Plain Language SummaryThe expression of female sexual behaviors in rodents relies on neuronal signaling within the ventromedial nucleus of the hypothalamus (VMH). Neurons located in the ventral lateral part of the VMH (vlVMH) release glutamate and use it as a mediator to transmit neuronal signals. These neurons are surrounded by astrocytes and may engage in metabolic interactions with them during the perinatal period. Astrocytes produce glutamine (Gln), which are transported into neurons as a precursor for producing glutamate. The vlVMH neurons that release glutamate depend on astrocytic Gln more heavily in female than in male pups. Perinatal disruption of Gln supply to neurons sex-differentially alters glutamate-mediated neuronal signaling and results in morphological changes in vlVMH neurons that resemble those of the opposite sex in adult animals. The present study reveals that perinatal blockade at various points of this metabolic pathway consistently decreased the expression of sex behavior of female rats, while it may only moderately reduce or left unaffected the sex behavior of male rats. Additionally, perinatal inhibition of Gln supply to neurons led to compensatory increases in a neuronal enzyme responsible for glutamate production in the hypothalamus of adult female rats. The results of the study demonstrate that an intact Gln-glutamate metabolic cycle between astrocytes and neurons during the perinatal period is necessary for the development of neuronal networks for proper sex behavior expression in female rats. The findings also suggest that behavioral defeminization could occur in the absence of high levels of E2 exposure in the brain of perinatal female rats.

Characterization and Functional Analysis of the 17-Beta Hydroxysteroid Dehydrogenase 2 (hsd17b2) Gene during Sex Reversal in the Ricefield Eel (Monopterus albus).

In mammals, 17-beta hydroxysteroid dehydrogenase 2 (Hsd17b2) enzyme specifically catalyzes the oxidation of the C17 hydroxyl group and efficiently regulates the activities of estrogens and androgens to prevent diseases induced by hormone disorders. However, the functions of the hsd17b2 gene involved in animal sex differentiation are still largely unclear. The ricefield eel (Monopterus albus), a protogynous hermaphroditic fish with a small genome size (2n = 24), is usually used as an ideal model to study the mechanism of sex differentiation in vertebrates. Therefore, in this study, hsd17b2 gene cDNA was cloned and its mRNA expression profiles were determined in the ricefield eel. The cloned cDNA fragment of hsd17b2 was 1230 bp, including an open reading frame of 1107 bp, encoding 368 amino acid residues with conserved catalytic subunits. Moreover, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis showed that hsd17b2 mRNA expressed strongly in the ovaries at early developmental stages, weakly in liver and intestine, and barely in testis and other tissues. In particular, hsd17b2 mRNA expression was found to peak in ovaries of young fish and ovotestis at the early stage, and eventually declined in gonads from the late ovotestis to testis. Likewise, chemical in situ hybridization results indicated that the hsd17b2 mRNA signals were primarily detected in the cytoplasm of oogonia and oocytes at stage I-II, subsequently concentrated in the granulosa cells around the oocytes at stage Ⅲ-Ⅳ, but undetectable in mature oocytes and male germ cells. Intriguingly, in ricefield eel ovaries, hsd17b2 mRNA expression could be significantly reduced by 17β-estradiol (E2) or tamoxifen (17β-estradiol inhibitor, E2I) induction at a low concentration (10 ng/mL) and increased by E2I induction at a high concentration (100 ng/mL). On the other hand, both the melatonin (MT) and flutamide (androgen inhibitor, AI) induction could significantly decrease hsd17b2 mRNA expression in the ovary of ricefield eel. This study provides a clue for demonstrating the mechanism of sexual differentiation in fish. The findings of our study imply that the hsd17b2 gene could be a key regulator in sexual differentiation and modulate sex reversal in the ricefield eel and other hermaphroditic fishes.

MiR-34 negatively regulates the expression of Dmrt and related genes in the testis of mud crab Scylla paramamosain

The mud crab (Scylla paramamosain) is a commercially significant marine decapod crustacean. Due to its obvious sexual dimorphism, the mechanism of sex differentiation and gonadal development has attracted significant research interest. The Dmrt (double-sex and mab-3 related transcription factor) genes are vital in animal gonadal development and sex differentiation. In the present study, miR-34 was predicted to target the 3′ end of Dmrt-1, idmrt-2, Dmrt-3, Dsx and Dmrt-like genes by prediction software, and the interactions between miR-34 and these Dmrt genes were validated by in vivo and in vitro experiments. Dual luciferase assay results indicated that miR-34 mimics/inhibitors co-transfected with plasmid vectors with 3′ end of Dmrt-1, idmrt-2, Dmrt-3, Dsx and Dmrt-like, respectively, led to a significant decrease/increase of fluorescence activity in HEK293T cells. In vivo experiments showed that injection of agomir-34 significantly inhibited Dmrt-1, idmrt-2, Dsx and Dmrt-like expression, while injection of antagomir-34 caused the opposite result. However, Dmrt-3 expression was not affected by injection of miR-34 reagents. Meanwhile, the expression of spermatogenesis and testicular development-related molecular marker genes (IAG, foxl2 and vasa) in mud crabs was significantly changed after injecting the miR-34 reagent in vivo. Furthermore, the result of immunoblotting proved that the expression level of Dmrt-like protein can be regulated by miR-34. These results imply that miR-34 is indirectly involved in sex differentiation and testicular development of S. paramamosain by regulating Dmrt-1, idmrt-2, Dsx and Dmrt-like genes.

A label-free quantification method for assessing sex from modern and ancient bovine tooth enamel

Identification of the sex of modern, fossil and archaeological animal remains offers many insights into their demography, mortality profiles and domestication pathways. However, due to many-factors, sex determination of osteological remains is often problematic. To overcome this, we have developed an innovative protocol to determine an animal’s sex from tooth enamel, by applying label-free quantification (LFQ) of two unique AmelY peptides ‘LRYPYP’ (AmelY;[M+2]2+\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{2+}$$\\end{document} 404.7212 m/z) and ‘LRYPYPSY’ (AmelY;[M+2]2+\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{2+}$$\\end{document} 529.7689 m/z) that are only present in the enamel of males. We applied this method to eight modern cattle (Bos taurus) of known sex, and correctly assigned them to sex. We then applied the same protocol to twelve archaeological Bos teeth from the Neolithic site of Beisamoun, Israel (8-th–7-th millennium BC) and determined the sex of the archaeological samples. Since teeth are usually better preserved than bones, this innovative protocol has potential to facilitate sex determination in ancient and modern bovine remains that currently cannot be sexed.

Spatiotemporal analysis of a population management intervention for dogs and cats in a municipality in central Mexico.

The overpopulation of dogs and cats has generated socioeconomic, political, and animal welfare problems, in addition to an important public health problem, due to the risk of zoonotic diseases. This study aimed to analyze the spatiotemporal coverage of canine and feline sterilization services provided by a governmental agency in the rural and urban areas of the municipality of Tequisquiapan, Querétaro. This cross-sectional study was conducted in Tequisquiapan's municipality, Querétaro, Mexico, from July 2019 to September 2022. The total number of sterilized dogs and cats was obtained from the monthly records of the Tequisquiapan Animal Health and Welfare Services Center (CESSBA, by its Spanish acronym). The collected information was related to the sterilized animals (species and sex) and their responsible guardians (sex and address). Access to dog and cat sterilization services was assessed using a geographic information system. Kernel density and directional ellipse tools were used to analyze the CESSBA coverage of care. Indicators were estimated to compare magnitudes and changes at the census tract level. A total of 4,489 animals were sterilized, with n = 2,611 (58%) dogs, of which 1,939 were female and 672 were male. The remaining n = 1,878 animals were cats, representing 42% of the total, with 1,257 females and 621 males. Up to 73% of the sterilized animals were owned by women. The population management of dogs and cats allowed us to increase the territorial coverage from 71.8% in 2019 to 92.3% in 2022. According to the temporal analysis (2019-2022), there was an annual upward trend in the number of sterilizations performed by CESSBA, with a rate of between 55.6 and 94.3 registered sterilizations per 100 inhabited dwellings and between 166.4 and 302.8 registered sterilizations per 1000 inhabitants. The analysis of the dog and cat sterilization service coverage revealed an upward trend, consisting of an increase in accessibility and participation of responsible caregivers who resided in both urban and rural areas of Tequisquiapan. Although it was not possible to evaluate the impact of the program, the use of georeferenced data and geospatial analysis showed that it can support the control of animal overpopulation.

Protocol for the systematic review of age and sex in preclinical models of age-correlated diseases

The translation of animal-based biomedical research into clinical research is often inadequate. Maximizing translation should be central to animal research on human diseases, guiding researchers in study design and animal model selection. However, practical considerations often drive the choice of animal model, which may not always reflect key patient characteristics, such as sex and age, impacting the disease's course. Despite diseases affecting both sexes, researchers frequently use male mice. To address this imbalance, journals and funding agencies have begun questioning the sex of animals used in studies and issued new guidelines. Conversely, the age of rodents is rarely discussed, even though many diseases primarily affect older patients. Young mice are commonly used, even in studies of diseases affecting older adults. Systematic comparisons between the age of rodents used and the age of patients in clinical trials are lacking. In this review, we systematically analyze the age and sex of mice used to model the five leading causes of global disability-adjusted life-years over the age of 75. We compare the results with the age and sex of patients in clinical trials focusing on Alzheimer's disease, stroke, type 2 diabetes mellitus, ischemic heart disease, and chronic obstructive pulmonary disease. We also analyze whether the age of the mice used has changed over the past decade. By systematically assessing the age and sex of the mice, we aim to initiate a discussion on the appropriate choice of animal model to improve the translatability of research results.

Unlocking perspectives on surgical sterilization in dogs and cats: A comprehensive study among Thai veterinary professionals

Gaining insights into the opinions and attitudes of veterinarians is essential for enhancing the sterilization rate, given their influential role in guiding pet owners. This study investigated the attitudes and practices of Thai veterinarians concerning surgical sterilization in dogs and cats. The survey was conducted from August 2022 to December 2022 and distributed through online and on-site questionnaires across all regions of Thailand. Seven hundred twenty-four veterinarians participated. A strong inclination toward sterilization for population control with a notable preference for female animals was revealed. The factors related to the necessity of sterilization in the opinion of Thai veterinarians were gender, age of veterinarians, and animal sex (P<0.05). Male veterinarians tended to assign less importance to sterilization, especially for male dogs (OR = 0.824), compared to their female counterparts. Older veterinarians tended to prioritize sterilization less than younger ones (OR = 0.985). Regarding animal’s sex, a preference for sterilizing females over males in both dogs and cats (OR = 0.291) was observed. Encouraging sterilization should be promoted equally among veterinarians of both genders, with particular emphasis on older male veterinary practitioners. Most veterinarians recommended sterilization between 4 and 6 months for female cats and 7–10 months for male cats, male dogs and female dogs. Overall, mean agreement scores for prepubertal gonadectomy were significantly higher (P<0.05) for female dogs and cats, and the only significant factor associated with these scores was the animal's sex. Veterinarians expressed more disagreement with prepubertal sterilization in males compared to females, with an OR of 0.33. There were some concerns in prepubertal sterilization such as growth and development problems, anesthesia risks, and urinary tract disorders. These insights observed in Thailand hold potential implications for other countries facing similar challenges in effectively managing pet overpopulation.

Evolution and regulation of animal sex chromosomes.

Animal sex chromosomes typically carry the upstream sex-determining gene that triggers testis or ovary development and, in some species, are regulated by global dosage compensation in response to functional decay of the Y chromosome. Despite the importance of these pathways, they exhibit striking differences across species, raising fundamental questions regarding the mechanisms underlying their evolutionary turnover. Recent studies of non-model organisms, including insects, reptiles and teleosts, have yielded a broad view of the diversity of sex chromosomes that challenges established theories. Moreover, continued studies in model organisms with recently developed technologies have characterized the dynamics of sex determination and dosage compensation in three-dimensional nuclear space and at single-cell resolution. Here, we synthesize recent insights into sex chromosomes from a variety of species to review their evolutionary dynamics with respect to the canonical model, as well as their diverse mechanisms of regulation.