Current State of In Vitro Embryo Production in African Lion ().

In the last 30-40 years, in vitro maturation (IVM) and fertilization (IVF) of domestic cat oocytes have been established as part of the panel of assisted reproduction technologies. As a representative of wild felids, the African lion is not yet considered endangered. Nevertheless, the zoo population management of the African lion itself as well as other closely related felids would benefit from the establishment of an IVF system.

Role of sex steroids and prostaglandins during the luteal life cycle in domestic cats and lynxes.

Although lynxes and domestic cats are both felids, their luteal life cycles differ. As in many species, corpora lutea (CLs) of domestic cats regress after pregnancy or pseudopregnancy. By contrast, CLs of lynxes do not functionally regress following the cycle of their formation.

Early preantral follicles of the domestic cat express gonadotropin and sex steroid signaling potential.

Key biomolecular processes, which regulate primordial ovarian follicle dormancy and early folliculogenesis in mammalian ovaries, are not fully understood. The domestic cat is a useful model to study ovarian folliculogenesis and is the most relevant for developing in vitro growth methods to be implemented in wild felid conservation breeding programs. Previously, RNA-sequencing of primordial (PrF), primary (PF), and secondary follicle (SF) samples from domestic cat implicated ovarian steroidogenesis and steroid reception during follicle development.

Desiccated cat spermatozoa retain DNA integrity and developmental potential after prolonged storage and shipping at non-cryogenic temperatures.

Purpose: To evaluate the DNA integrity and developmental potential of microwave-dehydrated cat spermatozoa after storage at - 20 °C for different time periods and/or overnight shipping on dry ice.

Methods: Epididymal spermatozoa from domestic cats were microwave-dehydrated on coverslips after trehalose exposure. Dried samples were either assessed immediately, stored for various duration at - 20 °C, or shipped internationally on dry ice before continued storage.

Amino acids activate mTORC1 to release roe deer embryos from decelerated proliferation during diapause.

Embryonic diapause in mammals leads to a reversible developmental arrest. While completely halted in many species, European roe deer () embryos display a continuous deceleration of proliferation. During a 4-mo period, the cell doubling time is 2 to 3 wk.

Decreasing glucocorticoid levels towards the expansion front suggest ongoing expansion in a terrestrial mammal.

Understanding the causes of range expansions in abundant species can help predict future species distributions. During range expansions, animals are exposed to novel environments and are required to cope with new and unpredictable stressors. Glucocorticoids (GCs) are mediators of the hormonal and behavioural mechanisms allowing animals to cope with unpredictable changes in the environment and are therefore expected to differ between populations at expansion edge and the historic range.

IGF-I Medium Supplementation Improves Singly Cultured Cat Oocyte Maturation and Embryo Development In Vitro.

Embryo production is a routine procedure in several species. However, in felids, the effectiveness of this approach is far behind that in the majority of laboratory species. The development of a suitable environment starts with the proper composition of culture media.

Comparison of Different Materials for Self-Pressurized Vitrification of Feline Oocytes-First Results.

Cryobanking is a crucial part on species conservation. Nowadays, there is no suitable protocol for vitrification of feline oocytes. Self-pressurized rapid freezing of different cell types proved to mimic the advantages of high pressure freezing.

Cloprostenol, a synthetic analog of prostaglandin F2α induces functional regression in cultured luteal cells of felids†.

In the present study, we investigated the effect of the synthetic analog of prostaglandin F2α (PGF2α)-cloprostenol-on cultured steroidogenic luteal cells of selected felid species over a 2-day culture period. The changes induced by cloprostenol were measured based on progesterone concentration and mRNA expression analysis of selected genes. Cloprostenol significantly reduced concentration of progesterone in cell culture medium of small luteal cells isolated from domestic cat corpora lutea (CL) at the development/maintenance stage (P < 0.

Signalling pathways and mechanistic cues highlighted by transcriptomic analysis of primordial, primary, and secondary ovarian follicles in domestic cat.

In vitro growth (IVG) of dormant primordial ovarian follicles aims to produce mature competent oocytes for assisted reproduction. Success is dependent on optimal in vitro conditions complemented with an understanding of oocyte and ovarian follicle development in vivo. Complete IVG has not been achieved in any other mammalian species besides mice.

Luteinizing Hormone Effect on Luteal Cells Is Dependent on the Corpus Luteum Stage in Felids.

The objective of this study was to investigate the effect of luteinizing hormone (LH) on steroidogenic luteal cells obtained from corpora lutea (CL) of the domestic cat and selected wild felids. Luteal cells were isolated enzymatically from CL at different developmental stages and cultured for two days in the presence and absence of 100 ng/mL LH, respectively. Functionality was assessed by progesterone (P4) accumulation in cell culture media determined by ELISA.

Maturation and fertilization of African lion (Panthera leo) oocytes after vitrification.

The African lion is an excellent model species for the highly endangered Asiatic lion. African lions reproduce well in zoos, leading to the fact that occasionally ovaries and testis are available for in-vitro experiments. We previously performed in-vitro maturation (IVM) and fertilization of lion oocytes and were able to produce advanced embryos after intracytoplasmic sperm injection (ICSI) with cryopreserved sperm.

Inhibition of Apoptotic Pathways Improves DNA Integrity but Not Developmental Competence of Domestic Cat Immature Vitrified Oocytes.

Being a model for endangered wild felids, cryopreservation protocols for domestic cat oocytes are under continuous development. Immature vitrified oocytes (VOs) are a valuable resource for fertility preservation programs, but they often degenerate after warming and their development is poor. Since the exact mechanisms are not clear, this study assessed whether vitrification might trigger two apoptotic markers (DNA fragmentation and caspase activity, Experiment I) and the effects of a chemical inhibitor (i.

Ovary cold storage and shipment affect oocyte yield and cleavage rate of cat immature vitrified oocytes.

In feline species, cooled transport of ovaries can be employed without detrimental effects to retrieve immature oocytes intended for in vitro embryo production purposes. Indeed, this is the most common way to collect gametes from gonads of wild, valuable animals after they die or are castrated far from specialized laboratories. However, fresh retrieved gametes are generally used, and their cryosensitivity is not known.

Sex steroids and glucocorticoid ratios in Iberian lynx hair.

Knowledge on species' reproductive biology is a fundamental pre-requisite of every conservation effort, but is often lacking. Sex steroids can provide valuable information for the assessment of reproductive success, whereas glucocorticoids are used to assess adrenocortical activity and stress-related bodily adaption. However, due to their perilous condition, access to animals is often difficult, which makes hormone measurement in non-invasively collected hair samples an attractive option.

Meiotic Status Does Not Affect the Vitrification Effectiveness of Domestic Cat Oocytes.

Cryopreservation is important for animal fertility and biodiversity. Unfortunately, cryopreservation of feline oocytes is still an experimental technique. The aims of this study were to analyze the potential toxicity of the cryoprotectants in the vitrification solution (VS) on cat oocytes and to investigate whether the meiotic status of oocytes influences their developmental potential after vitrification.

Preservation of female genetic resources in feline species.

The development of assisted reproduction techniques (ART) specifically for felids has been propagated for two main reasons: (i) most felids are threatened and faced with extinction in all or part of their native habitats (IUCN Red List of Threatened Species, www.catsg.org), and (ii) the domestic cat (Felis catus) can serve as a research model for the implementation of advanced assisted reproductive techniques (ART) to be applied in exotic cats.

Hair cortisol analyses in different mammal species: choosing the wrong assay may lead to erroneous results.

Wild animals are faced with a broad range of environmental stressors and research is needed to better understand their effect on populations. Hormone analysis based on enzyme immunoassays (EIAs) can provide valuable information on adrenocortical activity (stress), and assessment of cortisol in hair may allow the quantification of cortisol production. To validate hair hormone analysis, we compared two EIAs based on antibodies against cortisol-3-CMO-BSA and cortisol-21-HS-BSA for hair glucocorticoid (hGC) measurements in Egyptian mongoose, Iberian lynx, Alpine marmot, Asiatic black bear, spotted hyena and cheetah, with results obtained by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) measurements.

The antioxidative enzyme SOD2 is important for physiological persistence of corpora lutea in lynxes.

Corpora lutea (CL) are transient endocrine glands supporting pregnancy by progesterone production. They develop at the site of ovulation from the remaining follicle, are highly metabolically active and undergo distinct, transformative processes during their lifetime. In contrast to other species, CL of lynxes do not regress at the end of cycle, but remain functionally active (persist) for years.

Functional and Morphological Characterization of Small and Large Steroidogenic Luteal Cells From Domestic Cats Before and During Culture.

The current study aimed to isolate, culture and characterize small (SLC) and large (LLC) steroidogenic cells from the (CL) of non-pregnant domestic cats. Isolation of feline SLC was based on an enzymatic digestion of luteal tissue, whereas LLC were obtained by mechanical disruption of CL. To assess function of both cell types, progesterone secretion and mRNA expression of selected genes involved in steroid and prostaglandin synthesis were measured, as well as relative transcript abundance of hormone receptors and anti-oxidative enzymes, before and during culture.

Correction: Age, sex and storage time influence hair cortisol levels in a wild mammal population.

[This corrects the article DOI: 10.1371/journal.pone.

Age, sex and storage time influence hair cortisol levels in a wild mammal population.

The measurement of hair cortisol is increasingly used to understand the effect of natural and anthropogenic stressors on wild animals, but it is potentially confounded by individual, seasonal and sex-dependant variations in baseline cortisol secretion. This study validated an enzyme-linked immunoassay for hair cortisol measurement and characterized its baseline variation in a wild population of Egyptian mongoose. The analysis encompassed individuals of both sexes and all ages, across a range of geographic, environmental and seasonal conditions that the species experiences in Portugal allowing us to account for spatial, temporal and biological factors that contribute to hair cortisol variation.

Brilliant cresyl blue staining allows the selection for developmentally competent immature feline oocytes.

The outcome of in-vitro-maturation and in-vitro-fertilization of feline oocytes depends on the selection of high quality oocytes, and is often restricted to morphological criteria. The aim of this study was to test whether the Brilliant cresyl blue (BCB) staining is suitable for pre-selection of feline oocytes before in-vitro-maturation. Cumulus-oocytes-complexes (COC) were released from domestic cat ovaries obtained after ovariectomy and were subjected to BCB staining.

Diet changes alter paternally inherited epigenetic pattern in male Wild guinea pigs.

Epigenetic modifications, of which DNA methylation is the most stable, are a mechanism conveying environmental information to subsequent generations via parental germ lines. The paternal contribution to adaptive processes in the offspring might be crucial, but has been widely neglected in comparison to the maternal one. To address the paternal impact on the offspring's adaptability to changes in diet composition, we investigated if low protein diet (LPD) in F0 males caused epigenetic alterations in their subsequently sired sons.