First case of sterility associated with sex chromosomal abnormalities in a jenny

Chromosomal abnormalities are one of the main causes of genetic infertility in horses. Currently, their detection rate is rising due to the use of new diagnostic tools employing molecular markers linked to the sex chromosome pair. Despite genetic similarities, there are no previous reports of sterility associated with chromosomal abnormalities in the domestic donkey (Equus asinus). Hereby, we determined the presence of a chromosomal mosaicism in a female donkey with reproductive problems using molecular methodologies developed for horses. A two-and- a- half- year- old jenny characterized by morphological abnormalities of the reproductive tract was cytogenetically analysed using conventional and fluorescent techniques and a group of microsatellite markers (short tandem repeat, STR). At the same time, five ultrasound measures of the reproductive tract were taken and compared with eight contemporary jennies of the same breed. After slaughter, morphological examinations showed that the case study had a blind vaginal vestibule defining an empty pouch that covered the entrance of the cervical os. Histopathological studies demonstrated that this abnormal structure was compatible with a remnant hymen. Molecular markers, STR and fluorescent in situ hybridization determinations revealed that the animal was a 62, XX/61,X mosaic and, therefore, the first case of chromosomal abnormalities in the sex pair reported in donkeys.Instituto de Genética Veterinari

Genome Diversity and the Origin of the Arabian Horse

The Arabian horse, one of the world\u27s oldest breeds of any domesticated animal, is characterized by natural beauty, graceful movement, athletic endurance, and, as a result of its development in the arid Middle East, the ability to thrive in a hot, dry environment. Here we studied 378 Arabian horses from 12 countries using equine single nucleotide polymorphism (SNP) arrays and whole-genome re-sequencing to examine hypotheses about genomic diversity, population structure, and the relationship of the Arabian to other horse breeds. We identified a high degree of genetic variation and complex ancestry in Arabian horses from the Middle East region. Also, contrary to popular belief, we could detect no significant genomic contribution of the Arabian breed to the Thoroughbred racehorse, including Y chromosome ancestry. However, we found strong evidence for recent interbreeding of Thoroughbreds with Arabians used for flat-racing competitions. Genetic signatures suggestive of selective sweeps across the Arabian breed contain candidate genes for combating oxidative damage during exercise, and within the Straight Egyptian subgroup, for facial morphology. Overall, our data support an origin of the Arabian horse in the Middle East, no evidence for reduced global genetic diversity across the breed, and unique genetic adaptations for both physiology and conformation

Y-Chromosomal Insights into Breeding History and Sire Line Genealogies of Arabian Horses

The Y chromosome is a valuable genetic marker for studying the origin and influence of paternal lineages in populations. In this study, we conducted Y-chromosomal lineage-tracing in Arabian horses. First, we resolved a Y haplotype phylogeny based on the next generation sequencing data of 157 males from several breeds. Y-chromosomal haplotypes specific for Arabian horses were inferred by genotyping a collection of 145 males representing most Arabian sire lines that are active around the globe. These lines formed three discrete haplogroups, and the same haplogroups were detected in Arabian populations native to the Middle East. The Arabian haplotypes were clearly distinct from the ones detected in Akhal Tekes, Turkoman horses, and the progeny of two Thoroughbred foundation sires. However, a haplotype introduced into the English Thoroughbred by the stallion Byerley Turk (1680), was shared among Arabians, Turkomans, and Akhal Tekes, which opens a discussion about the historic connections between Oriental horse types. Furthermore, we genetically traced Arabian sire line breeding in the Western World over the past 200 years. This confirmed a strong selection for relatively few male lineages and uncovered incongruences to written pedigree records. Overall, we demonstrate how fine-scaled Y-analysis contributes to a better understanding of the historical development of horse breeds.Peer Reviewe

Whole genome analysis reveals aneuploidies in early pregnancy loss in the horse

The first 8 weeks of pregnancy is a critical time, with the majority of pregnancy losses occurring during this period. Abnormal chromosome number (aneuploidy) is a common finding in human miscarriage, yet is rarely reported in domestic animals. Equine early pregnancy loss (EPL) has no diagnosis in over 80% of cases. The aim of this study was to characterise aneuploidies associated with equine EPL. Genomic DNA from clinical cases of spontaneous miscarriage (EPLs; 14–65 days of gestation) and healthy control placentae (various gestational ages) were assessed using a high density genotyping array. Aneuploidy was detected in 12/55 EPLs (21.8%), and 0/15 healthy control placentae. Whole genome sequencing (30X) and digital droplet PCR (ddPCR) validated results. The majority of these aneuploidies have never been reported in live born equines, supporting their embryonic/fetal lethality. Aneuploidies were detected in both placental and fetal compartments. Rodents are currently used to study how maternal ageing impacts aneuploidy risk, however the differences in reproductive biology is a limitation of this model. We present the first evidence of aneuploidy in naturally occurring equine EPLs at a similar rate to human miscarriage. We therefore suggest the horse as an alternative to rodent models to study mechanisms resulting in aneuploid pregnancies

Article ID 604098, 5 pages Veterinary Clinical Medicine, Rural Animal Health Management, 1008 W. Hazelwood Drive, 223 Large Animal Clinic

The field diagnosis of constrictive pericardial effusion is often established on the pertinent pathognomonic physical examination findings, but the condition cannot be ruled out based on absence of these cardinal signs. Constrictive pericardial effusion is not always manifested by bilateral jugular venous distention and pulsation, brisket edema, and muffled heart sounds, all of which are considered the key points in the field diagnosis of pericardial effusion and hardware disease. This case will also document that the outcomes of hematology, serum biochemistry panels, and blood gas analysis can be totally inconsistent with passive venous congestion and constrictive pericardial effusion in cattle. Chest radiographic findings revealed radio dense, wire-like objects; the findings were suggestive but not conclusive for pericardial or pleural effusions, due to indistinguishable diaphragmatic outline and cardiopulmonary silhouette. Cardiac ultrasonography was found to be an excellent paraclinical diagnostic procedure for cases that potentially have traumatic pericarditis and constrictive pericardial effusion. Ultrasound-guided pericardiocentesis was also a valuable diagnostic aid in establishing a definitive diagnosis

Film processability and properties of polycaprolactone/thermoplastic starch blends

Nucleolar organizing regions (NORs) containing rDNA gene clusters have been assigned to the equine autosomes ECA1, ECA28, and ECA31. Active NORs (Ag-NORs) are associated with argyrophilic proteins, which allow them to be readily identified using silver staining techniques. Fluorescence in situ hybridization (FISH) for rDNA can also be used to visualize all NOR clusters in the nucleus, regardless of whether they are active or inactive. The present study analyzed the distribution and behavior of equine Ag-NOR and NOR clusters in horse spermatozoa and during male meiosis by FISH and silver staining. The NOR foci were observed to be variable in number, size, and shape, but were usually located centrally and appeared as one or two nucleolus-like structures in the spermatozoa head. Three distinctive FISH signals identified the NOR-bearing chromosome pairs during the synaptic cell stage of meiosis I. At diakinesis/metaphase I, as well as different stages of meiosis II, FISH signals clearly depicted the NOR-bearing sister chromatids. The synaptonemal complexes of primary spermatocytes consistently showed three rDNA foci following FISH, but variably demonstrated two or three Ag-NOR bodies following silver staining. We propose rDNA loss and gain during unequal crossing-over events could be both a direct and indirect cause of variation in equine NOR foci. Additionally, our cytogenetic analysis did not confirm the presence of a fourth pair of NORs-bearing chromosomes in the horse, which is contrary to previously mitotic published data. " 2012 Elsevier Inc.",,,,,,"10.1016/j.theriogenology.2011.08.034",,,"http://hdl.handle.net/20.500.12104/43253","http://www.scopus.com/inward/record.url?eid=2-s2.0-84855810848&partnerID=40&md5=d1c3616352e1f85af4312577ea287227",,,,,,"3",,"Theriogenology",,"57

Nucleolar organizer regions (NORs) distribution and behavior in spermatozoa and meiotic cells of the horse (Equus caballus)

Nucleolar organizing regions (NORs) containing rDNA gene clusters have been assigned to the equine autosomes ECA1, ECA28, and ECA31. Active NORs (Ag-NORs) are associated with argyrophilic proteins, which allow them to be readily identified using silver staining techniques. Fluorescence in situ hybridization (FISH) for rDNA can also be used to visualize all NOR clusters in the nucleus, regardless of whether they are active or inactive. The present study analyzed the distribution and behavior of equine Ag-NOR and NOR clusters in horse spermatozoa and during male meiosis by FISH and silver staining. The NOR foci were observed to be variable in number, size, and shape, but were usually located centrally and appeared as one or two nucleolus-like structures in the spermatozoa head. Three distinctive FISH signals identified the NOR-bearing chromosome pairs during the synaptic cell stage of meiosis I. At diakinesis/metaphase I, as well as different stages of meiosis II, FISH signals clearly depicted the NOR-bearing sister chromatids. The synaptonemal complexes of primary spermatocytes consistently showed three rDNA foci following FISH, but variably demonstrated two or three Ag-NOR bodies following silver staining. We propose rDNA loss and gain during unequal crossing-over events could be both a direct and indirect cause of variation in equine NOR foci. Additionally, our cytogenetic analysis did not confirm the presence of a fourth pair of NORs-bearing chromosomes in the horse, which is contrary to previously mitotic published data. © 2012 Elsevier Inc

Molecular characterization of the apoptosis-related SH3RF1 and SH3RF2 genes and their association with exercise performance in Arabian horses

Abstract Background Apoptosis plays an important role in the regulation of healthy tissue growth and development as well as in controlling the maintenance of homeostasis in exercising muscles. During an intensive physical effort, the regulation of cell death by apoptosis results in the replacement of unaccustomed muscle cells by new cells that are better suited to exercise. The aim of this study was to determine the expression of two genes (SH3FR1 and SH3RF2) that control apoptosis in muscle tissues during training periods characterized by different intensities. The gene expression levels were estimated using real-time PCR method in skeletal muscle biopsies collected from 15 Arabian horses (untrained, after an intense gallop phase, and at the end of the racing season). An association study was performed on 250 Arabian horses to assess the effect of the SH3RF2:c.796 T > C (p.Ser266Pro) variant on race performance traits in flat gallop-racing. Results A gene expression analysis confirmed a significant decrease (p  C missense variant was associated with selected racing performance traits, which is important information during the evaluation of horses’ exercise predisposition. The association results and frequencies of the CT and TT genotypes suggest the possibility of using SH3RF2 variant in selection to improve the racing performance of Arabian horses

Transcriptome analysis of equine sarcoids

Equine sarcoids are the most commonly detected skin tumours in Equidae. In the present research, a comparative transcriptomic analysis was performed which aimed at looking inside a tumour biology and identification of the expression profile as a potential source of cancer specific genes useful as biomarkers. We have used Horse Gene Expression Microarray data from matched equine sarcoids and tumour-distant skin samples. In total, 901 significantly differentially expressed genes (DEGs) between lesional and healthy skin samples have been identified (fold change ≥ 2; P < 0.05). The large subset of DEGs, with decreased expression, was associated with a suppression of malignant transformation, whereas several overexpressed genes were involved in the processes associated with growth and progression of a tumour or immune system activity. Our results, as a first to date, showed comprehensive transcriptome analysis of skin tumour in horses and pinpointed significant pathways and genes related with oncogenesis processes