Endogenous retrovirus ERV-DC8 highly integrated in domestic cat populations is a replication-competent provirus.

Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections in vertebrate genomes and are inherited by offspring. ERVs can produce pathogenic viruses through gene mutations or recombination. ERVs in domestic cats (ERV-DCs) generate feline leukemia virus subgroup D (FeLV-D) through viral recombination. Herein, we characterized the locus ERV-DC8, on chromosome B1, as an infectious replication-competent provirus. ERV-DC8 infected several cell lines, including human cells. Transmission electron microscopy of ERV-DC8 identified the viral release as a Gammaretrovirus. ERV-DC8 was identified as the FeLV-D viral interference group, with feline copper transporter 1 as its viral receptor. Insertional polymorphism analysis showed high ERV-DC8 integration in domestic cats. This study highlights the role, pathogenicity, and evolutionary relationships between ERVs and their hosts.

Molecular detection using hybridization capture and next-generation sequencing reveals cross-species transmission of feline coronavirus type-1 between a domestic cat and a captive wild felid.

Feline coronavirus (FCoV) infection normally causes mild or subclinical signs and is common in domestic cats. However, in some cats, FCoV infection can also lead to the development of feline infectious peritonitis (FIP)-a typically lethal disease. FCoV has two serotypes or genotypes, FCoV-1 and FCoV-2, both of which can cause FIP. The main difference between the genotypes is the viral spike (S) protein that determines tropism and pathogenicity, crucial mechanisms in the development of FIP. Subclinical infection and FIP have both been reported in wild felids, including in threatened species. Due to the high genetic variability of the S gene and the technical challenges to sequencing it, detection and characterization of FCoV in wild felids have mainly centered on other more conserved genes. Therefore, the genotype causing FIP in most wild felids remains unknown. Here, we report a retrospective molecular epidemiological investigation of FCoV in a zoological institution in the U.Ss. In 2008, a domestic cat (Felis catus) and a Pallas' cat (Otocolobus manul) sharing the same room succumbed to FIP. Using in situ hybridization, we detected FCoV RNA in different tissues of both felids. Using hybridization capture and next-generation sequencing, we detected, sequenced, and characterized the whole genome of the FCoV infecting both felids. Our data show for the first time that FCoV-1 can be transmitted between domestic and wild felids and extends the known host range of FCoV-1. Our findings highlight the importance of identifying the genotype causing FIP, to develop effective control measures. IMPORTANCE: Feline coronavirus (FCoV) is highly prevalent in domestic cats worldwide and has also been reported in wild felids, including endangered species, in which it has caused substantial population declines. Characterizing the genetic diversity of FCoV is crucial due to recent reports of novel pathogenic recombinant variants causing high mortality in feral cats in Cyprus. In this retrospective molecular epidemiology study, we used archived samples collected in a zoological institution in the U.S. in which a domestic and a wild felid succumbed to FCoV. Using hybridization capture (HC) and next-generation sequencing, we show for the first time that FCoV can be naturally transmitted between domestic and wild felids. We demonstrate the efficacy of HC for detecting and sequencing the whole genome of FCoV, which is essential to characterize its different genotypes.

Successful ultrasound-guided ovum pick-up (OPU) and subsequent in vitro embryo production in a domestic cat.

Ovum Pick Up (OPU) is a minimally invasive technique widely used in cattle and mares for oocyte retrieval, involving ultrasound-guided puncture of ovarian follicles. It has been demonstrated that this technique is safe for its repeated use in the same female without affecting her reproductive health, allowing for the retrieval of oocytes in individuals regardless of their reproductive status. The oocytes obtained through OPU can subsequently be used for in vitro embryo production (IVP) using assisted reproductive techniques (ARTs) or be cryopreserved in biobanks for their future use. Traditionally, the minimally invasive technique of choice performed in vivo in domestic and wild felines was LOPU (laparoscopic-guided ovum pick up). The present study was designed to explore if ultrasound-guided OPU in the domestic cat is safe and effective. In an initial series of ex vivo experiments (n = 92 ovaries, n = 434 oocytes), the effect of different aspiration pressures for oocyte collection was explored. These experiments identified 43 mmHg as the optimal aspiration pressure, resulting in the highest recovery rate and a favorable maturation and blastocyst rate. Subsequently, 16 grade I and II oocytes were retrieved by OPU and 101 oocytes were retrieved following ovariectomy and slicing. Sixteen oocytes obtained with each technique were subjected to in vitro maturation (IVM) and in vitro fertilization (IVF). A total of 14 presumptive zygotes were selected for in vitro culture (IVC) from each group (OPU and slicing), obtaining a cleavage rate of 57.1 % and 64.2 %, a morula rate of 28.5 % in both groups, and a blastocyst rate of 7.14 % and 14.2 % respectively. The hormonal stimulation protocol was well-tolerated, with no adverse effects observed. Moreover, no complications arose during the ovariectomy performed post-OPU. The use of this technique in domestic cats represents a significant step forward in terms of safety, replicability, and invasiveness, serving as a valuable model for its application in wild felids species. Additional research involving a greater number of animals is required to validate these encouraging findings.

Lipid content and G6PDH activity in relation to ooplasm morphology and oocyte maturational competence in the domestic cat model.

The aim of the study was to investigate the relationship between ooplasm morphology, lipid content, glucose-6-phosphate dehydrogenase activity (G6PDH) and maturation potential of domestic cat oocytes. Cumulus-oocyte complexes were classified according to ooplasm morphology: evenly dark (dCOC), heterogeneous/mosaic (hCOC), or light/transparent (lCOC), however only dCOCs are thought to be the best-quality, the remaining ones are usually rejected, therefore little is known about their intracellular properties. Lipid droplets (LDs) were visualized and quantified using Oil Red O. G6PDH activity was assessed before in vitro maturation (IVM), using the brilliant cresyl blue (BCB) test. IVM-control oocytes underwent IVM without BCB staining. The dCOCs and hCOCs had different patterns of LD spatial distribution, but similar amounts of lipid, although this tended towards being lower in hCOCs. Low G6PDH activity (BCB+) was observed in 74 %, 60 % and 24 % (P < 0.01) of dCOCs, hCOCs, and lCOCs, respectively. Significantly more BCB+ /oocytes than BCB-/oocytes reached the metaphase II stage in all groups. The maturation rate of BCB+ /hCOCs was higher than that of IVM/hCOC-controls (40 % v.s. 20 %, P < 0.001), and was comparable to that of BCB+ /dCOCs (54 %; P > 0.05). lCOCs were the smallest (P < 0.01), contained fewer (P < 0.01) lipids than dCOCs or hCOCs, and displayed reduced maturational potential. Overall, LD content and distribution, as well as G6PDH activity, in cat oocytes were strongly associated with ooplasm morphology and oocyte maturational competence. Deeper understanding of the intrinsic properties of oocytes with different ooplasm morphology using the domestic cat model, may be particularly important in the context of the conservation of endangered felids.

In search of freezability predictors for feline spermatozoa - osmotic challenge tests and markers of sperm membrane structure.

Semen cryopreservation is a crucial part of assisted reproductive techniques (ART) in animals, and recently it is gaining more and more attention among cat breeders. Even if fresh semen quality is good, sometimes spermatozoa do not survive freezing. The freezability prediction was widely studied in many species, but not in the domestic cat. The aim of this study was to verify the usefulness of osmotic challenge tests and membrane structure markers (Yo-Pro 1 and Merocyanine 540) for the prediction of the quality of post-thawed feline semen. Semen was collected by urethral catheterization from 22 male cats. After a basic evaluation of semen, 20×106 spermatozoa were cryopreserved; the rest were evaluated by flow cytometry for membrane integrity (SYBR-14/PI), acrosome status (lectin PNA/PI), mitochondrial potential (JC-1) and membrane stability (Yo-Pro 1/M540 staining). Hypo- and hyperosmotic challenge tests were also performed. The thawed samples were evaluated as fresh ones. The Pearson correlation between all parameters in fresh semen and all parameters in cryopreserved spermatozoa was assessed. Although some moderate correlations were found between the results of the osmotic tests and markers of sperm membrane stability (Yo-Pro 1 and Merocyanine 540) and post-thaw semen quality parameters, the predictive value of studied markers was rather weak - no cut-off values could be established and, based on regression models, they explained less than 40 % of variability in post-thaw quality. Our results confirm that cryodamage is a complex matter, in which many different factors play a role, affecting sperm motility and membrane integrity differently.

Description of Babesia galileei sp. nov. A Piroplasmid species causing severe disease in domestic cats.

BACKGROUND: Babesiosis is a tick-borne infection caused by piroplasmid protozoa and associated with anemia and severe disease in humans, domestic animals and wildlife. Domestic cats are infected by at least six Babesia spp. that cause clinical disease. METHODS: Infection with a piroplasmid species was detected by microscopy of stained blood smears in three sick cats from Israel. Genetic characterization of the piroplasmid was performed by PCR amplification of the 18S rRNA, cytochorme B (CytB) and heat shock protein 70 (HSP70) genes and the internal transcribed spacer (ITS) locus, DNA sequencing and phylogenetic analysis. In addition, Haemaphysalis adleri ticks collected from two cats were analyzed by PCR for piroplasmids. RESULTS: The infected cats presented with anemia and thrombocytopenia (3/3), fever (2/3) and icterus (1/3). Comparison of gene and loci sequences found 99-100% identity between sequences amplified from different cats and ticks. Constructed phylogenetic trees and DNA sequence comparisons demonstrated a previously undescribed Babesia sp. belonging to the Babesia sensu stricto (clade X). The piroplasm forms detected included pear-shaped merozoite and round-to-oval trophozoite stages with average sizes larger than those of Babesia felis, B. leo and B. lengau and smaller than canine Babesia s.s. spp. Four of 11 H. adleri adult ticks analyzed from cat # 3 were PCR positive for Babesia sp. with a DNA sequence identical to that found in the cats. Of these, two ticks were PCR positive in their salivary glands, suggesting that the parasite reached these glands and could possibly be transmitted by H. adleri. CONCLUSIONS: This study describes genetic and morphological findings of a new Babesia sp. which we propose to name Babesia galileei sp. nov. after the Galilee region in northern Israel where two of the infected cats originated from. The salivary gland PCR suggests that this Babesia sp. may be transmitted by H. adleri. However, incriminating this tick sp. as the vector of B. galilee sp. nov. would require further studies.

Evaluating undesired scratching in domestic cats: a multifactorial approach to understand risk factors.

Introduction: Despite being a natural feline behavior, scratching can become undesirable from a human perspective when directed at household items. This complex behavior can stem from various motivations, ranging from individual cat characteristics to environmental factors. This study investigates the factors influencing the increased level of undesirable scratching behavior in domestic cats, considering both cat-related and environmental aspects. Methods: Data from 1,211 cats were collected for this study. An online questionnaire comprising three sections was utilized. The first section gathered caregiver demographics, while the subsequent section examined aspects of cats' daily routines, social interactions, environments, behaviours, and temperaments. The final section assessed the frequency and intensity of undesirable scratching behavior in cats. Scratching behavior was evaluated based on a combined scratching index. Results: The study suggests that the presence of a child may be associated with scratching episodes in the home environment. Additionally, factors such as play duration, playfulness, and nocturnal activity were identified as significant contributors to heightened scratching levels (p ≤ 0.05). Aggressiveness and disruptiveness also played significant roles in increased scratching behavior (p ≤ 0.05). The location of scratching posts emerged as a significant factor, with posts placed in areas frequented by the cat being more effective in redirecting scratching behavior (p ≤ 0.05). Discussion: This study reveals several significant associations between cat characteristics, nocturnal activity and play, as well as the environment. It underscores the multifaceted nature of undesirable scratching behavior and emphasizes the importance of comprehensively understanding both the individual characteristics of the cat and its environment to effectively address this behavior.

Feline Cognition and the Role of Nutrition: An Evolutionary Perspective and Historical Review.

Research into cognition in cats and the impact of nutrition on cat cognitive health lags behind that in dogs but is receiving increased attention. In this review, we discuss the evolutionary history of the domesticated cat, describe possible drivers of domestication, and explore the interrelationships between nutrition and cat cognition. While most cat species are solitary, domesticated cats can live in social groups, engage in complex social encounters, and form strong attachments to humans. Researchers have recently started to study cat cognition using similar methods as those developed for dogs, with an initial primary focus on perception and social cognition. Similar to dogs, cats also show cognitive and behavioral changes associated with stress and aging, but these signs are often gradual and often considered a consequence of natural aging. Despite the fundamental role of nutrition in cognitive development, function, and maintenance, research into the association between nutrition and cognition in cats is only preliminary. Ultimately, additional research is needed to gain a full understanding of cat cognition and to explore the role of nutrition in the cognitive health of cats to help improve their welfare.

Morphological evaluation of adult domestic cat testicular biopsy after vitrification.

Testicular biopsies (9 mm3) from domestic cats (n = 10) submitted to orchiectomy were submitted to equilibrium vitrification in the presence of ethylene glycol (EG) alone or combined with dimethylsulfoxide (DMSO) as intracellular cryoprotectants, and sucrose or trehalose as extracellular cryoprotectants. The samples were vitrified with 40% EG or 20% EG + 20% DMSO, plus 0.1 M or 0.5 M of sucrose or trehalose. The study was divided into Step 1 and Step 2. In Step 1, intratubular cells (spermatogonia, spermatids, spermatocytes, and Sertoli cells) were quantified and classified as intact or degenerated (pyknotic and/or vacuolated cells). Cryodamage of seminiferous cords was determined by spermatogonia and Sertoli cell scoring of nuclei alterations, tubular basement membrane detachment, epithelium shrinkage, and tubular measures (total area, epithelium area, larger and smaller diameter, and height of the epithelium). In Step 2, Hoechst 33342 stain and propidium iodide (PI) fluorescent stain were used to assess the cell viability of the four best experimental groups in Step 1. The effect of treatments on all analyses was accessed using analysis of variance (ANOVA), and Fisher's post hoc test at P < 0.05 significance was considered. In Step 1, the mean percentage of spermatogonia and Sertoli cells morphological integrity did not show a difference when using both sugars at different concentrations, but their morphology was more affected when DMSO was used. EG use associated with 0.1 M of sucrose or trehalose positively affected spermatocyte and spermatid morphology, respectively. The larger diameter and epithelium height of seminiferous tubules were increased using DMSO plus 0.5 M sucrose and DMSO plus 0.1 M trehalose. The changes in spermatogonial/Sertoli nucleoli visualization were best scored in the EG groups, while the nuclei condensation was lower with sucrose. The basement membrane was satisfactorily preserved with 0.1 M sucrose. In Step 2, the percentage of cell viability was higher when EG plus 0.1 M sucrose was used. Therefore, DMSO's negative effect on the vitrification of testicular biopsies of adult domestic cats was evident. The EG plus 0.1 M of sucrose or trehalose associations are the most suitable CPAs to preserve the testicular histology structure of adult domestic cats in vitrification.

Identifying animal behaviours from accelerometers: Improving predictive accuracy of machine learning by refining the variables selected, data frequency, and sample duration.

Observing animals in the wild often poses extreme challenges, but animal-borne accelerometers are increasingly revealing unobservable behaviours. Automated machine learning streamlines behaviour identification from the substantial datasets generated during multi-animal, long-term studies; however, the accuracy of such models depends on the qualities of the training data. We examined how data processing influenced the predictive accuracy of random forest (RF) models, leveraging the easily observed domestic cat (Felis catus) as a model organism for terrestrial mammalian behaviours. Nine indoor domestic cats were equipped with collar-mounted tri-axial accelerometers, and behaviours were recorded alongside video footage. From this calibrated data, eight datasets were derived with (i) additional descriptive variables, (ii) altered frequencies of acceleration data (40 Hz vs. a mean over 1 s) and (iii) standardised durations of different behaviours. These training datasets were used to generate RF models that were validated against calibrated cat behaviours before identifying the behaviours of five free-ranging tag-equipped cats. These predictions were compared to those identified manually to validate the accuracy of the RF models for free-ranging animal behaviours. RF models accurately predicted the behaviours of indoor domestic cats (F-measure up to 0.96) with discernible improvements observed with post-data-collection processing. Additional variables, standardised durations of behaviours and higher recording frequencies improved model accuracy. However, prediction accuracy varied with different behaviours, where high-frequency models excelled in identifying fast-paced behaviours (e.g. locomotion), whereas lower-frequency models (1 Hz) more accurately identified slower, aperiodic behaviours such as grooming and feeding, particularly when examining free-ranging cat behaviours. While RF modelling offered a robust means of behaviour identification from accelerometer data, field validations were important to validate model accuracy for free-ranging individuals. Future studies may benefit from employing similar data processing methods that enhance RF behaviour identification accuracy, with extensive advantages for investigations into ecology, welfare and management of wild animals.

Fatty acid composition and biophysical characteristics of the cell membrane of feline spermatozoa.

Sperm membrane composition and biophysical characteristics play a pivotal role in many physiological processes (i.e. sperm motility, capacitation, acrosome reaction and fusion with the oocyte) as well as in semen processing (e.g. cryopreservation). The aim of this study was to characterize the fatty acid content and biophysical characteristics (anisotropy, generalized polarization) of the cell membrane of domestic cat spermatozoa. Semen was collected from 34 adult male cats by urethral catheterization. After a basic semen evaluation, the fatty acid content of some of the samples (n = 11) was evaluated by gas chromatography. Samples from other individuals (n = 23) were subjected to biophysical analysis: membrane anisotropy (which is inversely proportional to membrane fluidity) and generalized polarization (describing lipid order); both measured by fluorimetry at three temperature points: 38 °C, 25 °C and 5 °C. Spermatozoa from some samples (n = 10) were cryopreserved in TRIS egg yolk-glycerol extender and underwent the same biophysical analysis after thawing. Most fatty acids in feline spermatozoa were saturated (69.76 ± 24.45%), whereas the polyunsaturated fatty acid (PUFA) content was relatively low (6.12 ± 5.80%). Lowering the temperature caused a significant decrease in membrane fluidity and an increase in generalized polarization in fresh spermatozoa, and these effects were even more pronounced following cryopreservation. Anisotropy at 38 °C in fresh samples showed strong positive correlations with viability and motility parameters after thawing. In summary, feline spermatozoa are characterized by a very low PUFA content and a low ratio of unsaturated:saturated fatty acids, which may contribute to low oxidative stress. Cryopreservation alters the structure of the sperm membrane, increasing the fluidity of the hydrophobic portion of the bilayer and the lipid order in the hydrophilic portion. Because lower membrane fluidity in fresh semen was linked with better viability and motility after cryopreservation, this parameter may be considered an important factor in determination of sperm cryoresistance.

A new Finnish flavor of feline coat coloration, "salmiak," is associated with a 95-kb deletion downstream of the KIT gene.

Cats with a distinctive white hair pattern of unknown molecular cause have been discovered in the Finnish domestic cat population. Based on the unique appearance of these cats, we have named this phenotype salmiak ("salty licorice"). The use of a commercially available panel test to genotype four salmiak-colored cats revealed the absence of all known variants associated with white-haired phenotypic loci: full White (W), Spotting (Ws) and the Birman white Gloves associated (wg) allele of the KIT proto-oncogene (KIT) gene. Whole-genome sequencing on two salmiak-colored cats was conducted to search for candidate causal variants in the KIT gene. Despite a lack of coding variants, visual inspection of the short read alignments revealed a large ~95 kb deletion located ~65 kb downstream of the KIT gene in the salmiak cats. Additional PCR genotyping of 180 domestic cats and three salmiak-colored cats confirmed the homozygous derived variant genotype fully concordant with the salmiak phenotype. We suggest the newly identified variant be designated as wsal for "w salmiak".

How Lazy Are Pet Cats Really? Using Machine Learning and Accelerometry to Get a Glimpse into the Behaviour of Privately Owned Cats in Different Households.

Surprisingly little is known about how the home environment influences the behaviour of pet cats. This study aimed to determine how factors in the home environment (e.g., with or without outdoor access, urban vs. rural, presence of a child) and the season influences the daily behaviour of cats. Using accelerometer data and a validated machine learning model, behaviours including being active, eating, grooming, littering, lying, scratching, sitting, and standing were quantified for 28 pet cats. Generalized estimating equation models were used to determine the effects of different environmental conditions. Increasing cat age was negatively correlated with time spent active (p < 0.05). Cats with outdoor access (n = 18) were less active in winter than in summer (p < 0.05), but no differences were observed between seasons for indoor-only (n = 10) cats. Cats living in rural areas (n = 7) spent more time eating than cats in urban areas (n = 21; p < 0.05). Cats living in single-cat households (n = 12) spent more time lying but less time sitting than cats living in multi-cat households (n = 16; p < 0.05). Cats in households with at least one child (n = 20) spent more time standing in winter (p < 0.05), and more time lying but less time sitting in summer compared to cats in households with no children (n = 8; p < 0.05). This study clearly shows that the home environment has a major impact on cat behaviour.

Sprayed Urine Emits a Pungent Odor due to its Increased Adhesion to Vertical Objects via Urinary Proteins Rather Than to Changes in its Volatile Chemical Profile in Domestic Cats.

Spraying urine on vertical objects by raising the tail is a commonly observed functional behavior for chemical communication in Felidae species, including domestic cats (Felis silvestris catus). The sprayed urine is recognized as a chemical signal for territorial ownership of their habitats. Previous studies reported that sprayed urine emits a more pungent odor than urine excreted from a squatting position. However, little is known about how sprayed urine acts as a strong scent mark in the environment. Here, we showed that sprayed urine originates only from bladder urine without any secretions, such as anal sac secretions, but it can effectively emit volatile organic compounds (VOCs) when smeared on vertical objects due to its strong adhesion. Chemical profiles of VOCs and odor qualities were similar between fresh sprayed urine and bladder urine sampled immediately after spraying from the same individuals. Meanwhile, feline-specific proteinuria arising from excretion of a carboxylesterase that produces a precursor of cat-specific odorants resulted in reduced surface tension of the urine and increased adhesion to vertical surfaces, which kept sprayed urine on the surfaces and led to the emission of large amounts of VOCs. In conclusion, proteinuria contributes to the emission of a strong odor through its enhanced adhesion to vertical objects without other secretions containing malodorous substances. These findings improve our understanding of the mechanism of scent marking via the spraying of urine for chemical communication in cats.

Conserved Functions of Orthohepadnavirus X Proteins to Inhibit Type-I Interferon Signaling.

Orthohepadnavirus causes chronic hepatitis in a broad range of mammals, including primates, cats, woodchucks, and bats. Hepatitis B virus (HBV) X protein inhibits type-I interferon (IFN) signaling, thereby promoting HBV escape from the human innate immune system and establishing persistent infection. However, whether X proteins of Orthohepadnavirus viruses in other species display a similar inhibitory activity remains unknown. Here, we investigated the anti-IFN activity of 17 Orthohepadnavirus X proteins derived from various hosts. We observed conserved activity of Orthohepadnavirus X proteins in inhibiting TIR-domain-containing adaptor protein inducing IFN-ß (TRIF)-mediated IFN-ß signaling pathway through TRIF degradation. X proteins from domestic cat hepadnavirus (DCH), a novel member of Orthohepadnavirus, inhibited mitochondrial antiviral signaling protein (MAVS)-mediated IFNß signaling pathway comparable with HBV X. These results indicate that inhibition of IFN signaling is conserved in Orthohepadnavirus X proteins.

Aberrant sparganosis in cat caused by Spirometra mansoni (Cestoda: Diphyllobothriidae): a case report.

BACKGROUND: Sparganosis is a rare zoonotic disease caused by plerocercoid larvae of the genera Spirometra or Sparganum (Cestoda: Diphyllobothriidae). The larvae of Spirometra generally do not undergo asexual reproduction, whereas those of Sparganum can induce proliferative lesions in infected tissues. This paper presents an unusual case of proliferative sparganosis due to infection with Spirometra mansoni in a cat, normally considered a definitive host of the species. CASE PRESENTATION: A 9-year-old male domestic cat was presented with a mass on the right side of the face that underwent progressive enlargement for 1 month. The morphological and histopathological examinations revealed multiple asexual proliferative cestode larvae in the lesions, suggestive of proliferative sparganosis. Next-generation sequencing analysis of formalin-fixed and paraffin-embedded specimens of surgically excised tissue indicated that the worm was Spirometra mansoni. CONCLUSION: Although S. mansoni a common tapeworm species found in the small intestine of domestic cats and dogs in Japan, proliferative sparganosis is extremely rare. This is the first confirmed case of proliferative sparganosis due to infection with S. mansoni in cat.

Characterization of the endogenous retrovirus-derived placenta-specific soluble protein EnvV-Fca from domestic cats.

Endogenous retroviruses (ERVs) are remnants of ancestral viruses in the host genome. The present study identified the expression of a defective retroviral env gene belonging to the ERV group V member Env (EnvV) in Felis catus (EnvV-Fca). EnV-Fca was specifically detected in the placental trophoblast syncytiotrophobic layer and expressed as a secreted protein in cultured cells. Genetic analyses indicated that EnvV2 genes are widely present in vertebrates and are under purifying selection among carnivores, suggesting a potential benefit for the host. This study suggests that birds, bats, and rodents carrying EnvV2 may play significant roles as intermediate vectors in spreading or cross-transmitting viruses among species. Our findings provide valuable insights into the evolution of ERV in vertebrate hosts.

Evaluation of a commercial proAKAP4 kit for the assessment of fresh and frozen-thawed feline spermatozoa.

ProAKAP4 is gaining increasing attention as a potential marker of semen quality in many species, but while there is a commercial kit for assessing proAKAP4 in the domestic cat, there are no publications about its use. The aim of this study was to evaluate the commercial proAKAP4 kit - Cat 4MID® Kit (SPQI - 4BioDx, Lille, France) for the assessment of feline semen. Semen was collected from 54 male cats by urethral catheterization. After a basic semen evaluation (subjective motility, CASA, viability, morphology), proAKAP4 levels in each sample were assessed using the Cat 4MID® Kit according to the manufacturer's protocol or with some modifications related to incubation time, sample storage conditions and number of spermatozoa used. Finally, the Spearman correlation of proAKAP4 concentration and sperm motility parameters was calculated. The most reliable results (acceptable intraassay coefficient of variation) were obtained with an optimized protocol of overnight incubation and isolation of proAKAP4 protein from 1 × 106 spermatozoa stored at -80°C. For fresh semen, there were no significant correlations between proAKAP4 concentration and sperm motility parameters, despite a strong correlation between motility parameters and sperm viability and morphology. A predominant effect of other sperm parameters and highly variable performance of lysis buffer question the usefulness of Cat 4MID® Kit for the assessment of feline semen. For frozen-thawed semen, there was a moderate, negative correlation between proAKAP4 concentration and two CASA parameters, VAP and VSL. As there were no correlations between proAKAP4 concentration in fresh semen and motility parameters in cryopreserved samples, proAKAP4 cannot be used as freezability marker in cats. More studies are needed to establish potential correlation with long-lasting motility.

Feline sporotrichosis due to Sporothrix globosa in the Metropolitan region of Buenos Aires: A case study

Abstract We describe here the first case of feline sporotrichosis caused by Sporothrix globosa, occurring outside the epizootic area of Buenos Aires province, Argentina. Unlike cases reported with Sporothrix brasiliensis, on this occasion there was no clinical or serological evidence of zoonotic transmission through scratches or bites from the sick cat to the attending veterinarian or the person responsible for its care. This report aimed to improve the knowledge about the pathogenic profile of S. globosa.

Resumen En este trabajo se describe el primer caso de esporotricosis felina causada por Sporothrix globosa fuera del área epizoótica de Buenos Aires. A diferencia de los casos documentados de Sporothrix brasiliensis, en este no hubo evidencia clínica ni serológica de transmisión zoonótica por arañazos o mordeduras del gato enfermo a su dueño ni al veterinario que lo atendió. Con este reporte se espera contribuir a un mejor conocimiento sobre el perfil patogénico de S. globosa.

Prolonged cold-preservation of domestic cat ovarian tissue is improved by extracellular solution but impaired by the fragmentation of ovary.

For domestic cats ovaries, recommended cold-storage limit is 24 h in Phosphate Buffered Saline (PBS) or Dulbecco`s PBS (DPBS). Here, we attempted to verify wheatear cat ovaries may benefit from more complex solutions during prolonged cold-storage (>24 h). First, the preservation capabilities of extracellular (SP+), intracellular (UW) solutions and DPBS supplemented with glutathione (DPBS+GSH) were compared using ovary fragments from the same ovary (n=10). Intact ovary stored in DPBS served as a control. Ovaries were kept at 4 °C for 48 h, and 72 h. In the second experiment, first ovary was stored in DPBS, second in SP+ or UW solution for 48 h (n = 12). Ovaries pairs stored in DPBS for 24 h served as a control (n=8). Tissue samples were evaluated directly after cold-storage and after following 24 h in vitro culture. Ovarian follicle morphology, apoptosis rates (cleaved caspase-3, TUNEL), and follicular growth activation (Ki-67) were assessed. Ovary fragmentation impaired follicular morphology preservation upon cold-storage comparing to intact ovary. However, ovarian fragments stored in UW for 48 h and in SP+ for 72 h presented better morphology than DPBS+GSH group. Comparison of intact ovaries cold-storage for 48 h showed that SP+ provided superior follicular morphology over DPBS, and it was comparable to the outcome of 24-hour storage. No follicular activation after in vitro culture was observed. Nevertheless, tissue culture increased considerably caspase-3 cleavage and TUNEL detection. The ovary fragmentation prior to cold-storage is not recommended in domestic cats. Replacement of DPBS with SP+ solution for whole ovary and UW solution for ovarian tissue fragments improves follicular structure preservation during 48-hour cold-storage.