Ann Van Soom

• DVM, PhD
• Head of Department at Ghent University

As the global population continues to grow, the demand for sustainable food production methods becomes increasingly critical. This study investigates the presence of chromosomal abnormalities in bovine embryonic stem cells (bESCs), which hold potential for innovative food sources such as cultured meat. We derived three bESC lines from day-eight pos...

Extracellular vesicles (EVs), from follicular fluid seem to play a significant role in communication within ovarian follicles in several species. The present study aimed to examine the supporting effect of follicular fluid derived small EVs (FF-sEVs) during in vitro maturation (IVM) of bovine cumulus-oocyte complexes (COCs) under conditions of dist...

Whole-genome (WG) abnormalities, such as uniparental diploidy and triploidy, cause fetal death. Occasionally, they coexist with biparental diploid cells in live births. Understanding the origin and early development of WG abnormal blastomeres is crucial for explaining the formation of androgenotes, gynogenotes, triploidy, chimerism, and mixoploidy....

In brief Bulls are selected for field fertility and semen quality, but traits such as polyspermy are not considered and can increase aneuploidy during in vitro embryo production. This study links bull-specific proteomic signatures to polyspermy and embryo quality, further refining bull selection criteria. Abstract Male fertility plays a pivotal ro...

Over the past decade, research on embryo-derived extracellular vesicles (EVs) has unveiled their critical roles in embryonic development and intercellular communication. EVs secreted by embryos are nanoscale lipid bilayer vesicles that carry bioactive cargo, including proteins, lipids, RNAs, and DNAs, reflecting the physiological state of the sourc...

Benign prostatic hyperplasia (BPH) is a common condition in intact male dogs and a leading cause of subfertility. While surgical and chemical castration are effective treatments for BPH, managing this condition in breeding dogs is challenging due to the desire to preserve reproductive function. This study systematically reviews medical treatments f...

Introduction Sperm cryopreservation is a valuable technique for storing valuable canine genetics. However, little is known concerning the fate of frozen sperm stored in a sperm bank. This study aimed to characterize dogs presented for sperm cryopreservation and describe the use and popularity of frozen sperm in the Netherlands and Belgium over rece...

The study investigated whether bacterial seeding occurs in utero in dogs and cats using a multi-technique approach, including 16S rRNA gene sequencing, culture, and fluorescence in situ hybridization (FISH). Healthy pregnant bitches and queens (n=8) undergoing ovariohysterectomy between 30 and 45 days of gestation were included. Placenta and amniot...

Previous studies in the horse highlight the potential benefit of prolonged in vitro maturation (IVM) (34 h) compared to short IVM (24 h) with or without prior oocyte holding, but little is known about the optimal IVM duration within this interval. To determine the effect of oocyte holding and duration of IVM ranged between 28 and 34 h on nuclear ma...

Extracellular vesicles (EVs) contain microRNAs (miRNAs), which are important regulators of embryonic development. Nevertheless, little is known about the precise molecular processes controlling blastocyst development and quality. In a previous study, we identified bta-miR-665 as one of the miRNAs more abundantly present in extracellular vesicles of...

Introduction The increasing prevalence of infertility in male dogs in clinical practice mirrors current trends seen in human medicine. Acquired infertility is notably more common in dogs compared to congenital causes, with conditions such as testicular degeneration leading to irreversible loss of fertility. Current diagnostic methods for testicular...

The declining African and Asian elephant populations emphasize the importance of a backup population. Successful reproduction in captivity plays a key role in maintaining such a genetically diverse ex situ population but is challenged by reproductive loss in the form of abortions and stillbirths. The elephants' biphasic prolactin pattern led us to...

Background Microbial colonization during early life has a pivotal impact on the host health, shaping immune and metabolic functions, but little is known about timing and features of this process in dogs. The objectives of this study were to characterize the first step of intestinal microbiota development in naturally delivered canine puppies and to...

Little is known regarding the association between a mare's body condition score (BCS) and the ovum pick-BCS on oocyte developmental competence and to detect if the BCS can determine the mare's ability to produce embryos in vitro. Overall, 107 OPU-ICSI sessions were performed in Warmblood and Quarter mares (n at the Faculty of Veterinary Medicine, G...

Background Within the follicular fluid, extracellular vesicles (EVs) guide oocyte growth through their cargo microRNAs (miRNAs). Here, we investigated the role of EVs and their cargo miRNAs by linking the miRNAs found in EVs, derived from the fluid of an individual follicle, to the ability of its oocyte to become a blastocyst (competent) or not (no...

Whole-genome (WG) abnormalities, such as uniparental diploidy and triploidy, cause fetal death. Occasionally, they coexist with biparental diploid cells in live births. Understanding the origin and early development of WG abnormal blastomeres is crucial for explaining the formation of androgenotes, gynogenotes, triploidy, chimerism, and mixoploidy....

Study question Can CAPA-IVM (Biphasic in-vitro maturation) with C-type natriuretic peptide (CNP), followed by in vitro maturation (IVM) improve ovarian tissue oocyte (OTO) maturation in transgender patients? Summary answer CAPA-IVM did not show any significant difference in maturation competence and frequency of chromosomal aberrations when compar...

We recently developed re-differentiated equine oviduct epithelial cell (REOEC) monolayers demonstrating various in vivo morphological characteristics, but lacking secondary ciliation. In this study, we evaluated the effects of fetal bovine serum, reproductive steroid hormones, Wnt- and Notch ligands and inhibitors, and different EOEC seeding densit...

Maternal investment influences the survival and reproduction of both mothers and their progeny and plays a crucial role in understanding individuals’ life-history and population ecology. To reveal the complex mechanisms associated with reproduction and investment, it is necessary to examine variations in maternal investment across species. Comparis...

Simple Summary Benign prostatic hyperplasia is a common condition in older intact male dogs, and it is often initially lacking in noticeable clinical signs. Due to this asymptomatic nature, it is frequently overlooked in clinical practice. Our study aimed to develop a simplified non-invasive examination plan for the early detection of subclinical b...

Transfer RNA-derived small RNAs (tsRNAs) have been shown to be involved in early embryo development and repression of endogenous retroelements in embryos and stem cells. However, it is unknown whether tsRNAs also regulate embryo hatching. In this study, we mined the sequencing data of a previous experiment in which we demonstrated that the microRNA...

The microbiome of the reproductive tract is an area of research in full development. Specifically, the microbiome may be involved in reproductive health, disease, and pregnancy outcomes, as has been shown in humans and animals, including dogs. The aim of the present review was to summarize current knowledge on the microbiome of the canine reproduct...

STUDY QUESTION Is pronuclear transfer (PNT) capable of restoring embryo developmental arrest caused by cytoplasmic inferiority of in vitro grown (IVG) mouse oocytes? SUMMARY ANSWER PNT to in vivo matured cytoplasm significantly improved embryo development of IVG mouse oocytes, leading to living, fertile offspring. WHAT IS KNOWN ALREADY In vitro f...

The in vitro production of equine embryos via ovum pickup (OPU) and intracytoplasmic sperm injection (ICSI) has increased rapidly. There is a marked effect of the individual mare on the outcome of OPU-ICSI, but little is known about the influence of the mare's health condition. This study aimed to investigate the potential associations between the...

Cumulus expansion is an important indicator of oocyte maturation and has been suggested to be indicative of greater oocyte developmental capacity. Although multiple methods have been described to assess cumulus expansion, none of them is considered a gold standard. Additionally, these methods are subjective and time-consuming. In this manuscript, t...

In brief MicroRNAs (miRNAs) carried in extracellular vesicles are one of the essential factors for embryo development. This study demonstrates that miRNA-146 b has negative impacts on the quality and development of bovine embryos and also shows its higher expression in non-blastocyst embryos and related EVs. Abstract MicroRNAs (miRNAs), which can...

Introduction An optimized collection method and freezing protocol for preservation of epididymal spermatozoa remains a topic of interest to many scientists. The current study focused on the collection and preservation of canine epididymal spermatozoa. During the process of collection of canine epididymal spermatozoa, blood content can occur, which...

Simple Summary MicroRNAs (miRNAs) are small biomolecules that can indicate the presence of certain diseases, including cancer. They are stable and can be easily detected in blood and urine samples. Here we review the different roles of a specific miRNA, miR-665, in several cancer types and evaluate its potential as biomarker for early detection and...

In brief Opposing conclusions have been drawn regarding the presence of viable bacteria in the healthy pregnant uterus. Current evidence in humans and animals suggests that fetomaternal tissues present only traces of bacteria whose viability is still to be proven. Abstract The debate about the pioneer colonization of the fetus is still open, being...

Abstract This Scientific Report addresses a mandate from the European Commission according to Article 31 of Regulation (EC) No 178/2002 on the welfare of cats and dogs in commercial breeding establishments kept for sport, hunting and companion purposes. The aim was to scrutinise recent recommendations made by the EU Platform on Animal Welfare Volun...

Epididymal spermatozoa obtained post mortem are considered a valuable source of genetic material which is often irrevocably lost. This makes these gametes constitute a key element in protection and restitution programs. The wisent ( Bison bonasus , Linnaeus 1758) is a species that survived in zoos after extinction from its natural habitat. This res...

Introduction In tomcats, epididymal spermatozoa provide an additional source of male gametes available for cryopreservation. While this procedure is feasible, the survival rate and motility of epididymal cat spermatozoa are both low after thawing. Cryopreservation is known to induce oxidative stress in spermatozoa, with mitochondria and the plasma...

In different species, embryonic chromosomal aneuploidies are a major cause of developmental failure. The increasing number of equine embryos being produced worldwide provides the opportunity to characterize and rank or select embryos based on their genetic profile prior to transfer. Here, we explore the possibility of generic, genome-wide preimplan...

Study question Is the nuclear transfer technology able to overcome the compromised embryonic development of in vitro cultured secondary follicles from young B6D2 mice? Summary answer Nuclear transfer technology was able to restore embryonic development to levels similar of in vivo grown oocytes. What is known already In vitro follicle culture has...

Study question Can CAPA-IVM (Biphasic in-vitro maturation) with C-type natriuretic peptide (CNP), followed by in vitro maturation (IVM) improve ovarian tissue oocyte (OTO) maturation in transgender patients? Summary answer Biphasic CAPA-IVM did not show any significant difference in maturation competence and genetic variations when compared with i...

Simple Summary Oocyte maturation is a complex process in which the oocyte acquires the capacity to be fertilized and to support embryo development. Although oocyte maturation in vitro has undergone significant advancements, the systems that are currently in place still need to be further optimized. This study aimed to examine alternative culture sy...

Simple Summary This preliminary study aimed to assess the presence of bacteria in pregnancy tissues belonging to healthy canine and feline feto-maternal units at term. Specifically, it included bitches and queens undergoing elective cesarean sections and their first extracted fetus. The placental side of the endometrium, amniotic fluid, and meconiu...

Simple Summary Many species are threatened with extinction. A consequence of the decreasing population sizes is the loss of genetic diversity. To maintain this genetic diversity, establishing genetic resource banks can be part of the solution. These banks contain, amongst others, sperm and oocytes, which can be used to produce offspring through art...

The application of trans-vaginal ovum pick up (OPU) and intracytoplasmic sperm injection (ICSI) is well established for commercial in vitro embryo production in horses. These assisted reproductive techniques are especially applied during the non-breeding season of the mare. However, little is known about how the health of the oocyte donor may affec...

Study question: Can spindle transfer (ST) overcome inferior embryonic development of in vitro matured ovarian tissue oocytes (OTO-IVM) originating from testosterone-treated transgender men? Summary answer: ST shows some potential to overcome the embryo developmental arrest observed in OTO-IVM oocytes from transgender men. What is known already:...

In the last decade, in vitro embryo production in horses has become an established clinical practice, but blastocyst rates from vitrified equine oocytes remain low. Cryopreservation impairs the oocyte developmental potential, which may be reflected in the messenger RNA (mRNA) profile. Therefore, this study aimed to compare the transcriptome profile...

While human in vitro embryo production is generally performed individually, animal models have shown that culturing embryos in groups improves blastocyst yield and quality. Paracrine embryotrophins could be responsible for this improved embryo development, but their identity remains largely unknown. We hypothesize that supplementation of embryotrop...

Digital microfluidics (DMF) holds great potential for the alleviation of laboratory procedures in assisted reproductive technologies (ARTs). The electrowetting on dielectric (EWOD) technology provides dynamic culture conditions in vitro that may better mimic the natural embryo microenvironment. Thus far, EWOD microdevices have been proposed for in...

Embryo development is a dynamic process and critical stages may go unnoticed with the use of traditional morphologic assessments, especially the timing of embryonic divisions and aberrant zygotic cleavage patterns. Bovine embryo development is impaired after oocyte vitrification, but little is known about the underlying morphokinetic behavior. Here...

Digital microfluidics (DMF) holds great potential for the alleviation of laboratory procedures in assisted reproductive technologies (ARTs). Electrowetting on dielectric (EWOD) provides dynamic culture conditions in vitro that may better mimic the natural embryo microenvironment. Thus far, EWOD microdevices have been proposed for in vitro gamete an...

Cumulus expansion is an important indicator of oocyte maturation, often correlated with greater oocyte developmental capacity. Although multiple methods have been described to assess cumulus expansion, none of them is considered a gold standard. Additionally, these methods are subjective and time-consuming. Here, the reliability of three cumulus ex...

To achieve optimal vitrification, tissue structure and fragment size represent a challenge for obtaining sufficient cooling velocity. Theoretically, thin ovarian tissue fragments lead to higher surface contact, hence higher solute penetration. Another critical factor is the concentration of cryoprotectants (CPA): CPA toxicity may occur with high co...

The ovary and its hormones may have major effects on the in vitro developmental capacity of the oocytes it contains. We related intrinsic ovarian factors namely the presence of corpus luteum (CL) and/or dominant follicle (>8 mm) and the follicular count to cumulus expansion (CE), embryo development, and blastocyst quality in a bovine model. Cumulus...

In vivo matured oocytes exhibit higher developmental competence than those matured in vitro, but mimicking the in vivo environment by in vitro conditions has been challenging. Till now, conventional two-dimensional (2D) systems have been used for in vitro maturation of bovine cumulus-oocytes-complexes (COCs). However, using such systems may cause c...

The cumulus-oocyte complex (COC) is an oocyte surrounded by specialized granulosa cells, called cumulus cells. The cumulus cells surrounding the oocyte ensure healthy oocyte and embryo development. The maturity of COCs at oocyte retrieval may be used as an indicator to predict outcome of assisted reproductive technology (ART). Segmenting COCs is a...

Background During normal zygotic division, two haploid parental genomes replicate, unite and segregate into two biparental diploid blastomeres. Results Contrary to this fundamental biological tenet, we demonstrate here that parental genomes can segregate to distinct blastomeres during the zygotic division resulting in haploid or uniparental diploi...

Background The wisent ( Bison bonasus ) is a species that has undergone a population bottleneck. Homozygosity is prevalent within the population and may have a negative impact on semen quality in wisent bulls. Semen samples containing a large amount of functionally and morphologically impaired or dead spermatozoa have lower tolerance for cryopreser...

Study question Could collection temperature and spindle transfer (ST) potentially improve development of embryos derived from in vitro matured (IVM) ovarian tissue oocytes (OTO) of transgender men? Summary answer Spindle transfer, but not collection temperature, significantly improved embryo development of OTO-IVM oocytes from transgender men. Wh...

Study question Could extracellular vesicles (EVs) derived from spent media serve as a non-invasive quality marker for embryo implantation and pregnancy? Summary answer EVs isolated from spent media derived from human blastocysts that either did or didn’t establish a pregnancy after transfer differ in size, concentration, miRNA expression. What is...

BACKGROUND-AIM Reactive oxygen species (ROS) production is a physiological, dynamic process in all cells. However, ROS production is exacerbated during in vitro conditions mainly due to its high oxygen tension. This study aimed to evaluate the effect of lycopene supplementation into a serum-free culture medium on blastocyst development and quality....

Selenium is commonly used as antioxidant in a serum-free culture medium setting. However, lycopene has emerged as a potent antioxidant being twice as efficient as β-carotene and ten times as efficient as α-tocopherol with beneficial effects when supplemented in a serum-free maturation medium. Here we aimed to evaluate the effect of lycopene supplem...

In vitro embryo production has been rapidly evolved in horses, since the immature oocytes could be viably held overnight and shipped for intracytoplasmic sperm injection (ICSI). However, in facilities where ovum pick-up (OPU) and ICSI are performed in situ, direct in vitro maturation (IVM) can be performed. In a recent study, holding of oocytes fol...

Electrical stimulation of gametes and embryos as well as on-chip manipulation of microdroplets of culture medium serve as promising tools for assisted reproductive technologies (ARTs). Thus far, dielectrophoresis (DEP), electrorotation (ER) and electrowetting on dielectric (EWOD) proved compatible with most laboratory procedures offered by ARTs. Po...

Simple Summary Artificial reproductive techniques (ART), such as cryopreservation of sperm cells and artificial insemination, are useful tools for species conservation. However, there is relatively little information published about their introduction into clinical practice for wild felids. The aim of this paper was to describe how those techniques...

Significance Hatching from the zona pellucida is a prerequisite for embryo implantation and is less likely to occur in vitro for reasons unknown. Extracellular vesicles (EVs) are secreted by the embryo into the culture medium. Yet the role that embryonic EVs and their cargo microRNAs (miRNAs) play in blastocyst hatching has not been elucidated, par...

This study evaluated how semen selection by single layer centrifugation (SLC) with Canicoll affects semen freezability in dogs. A total of eighteen ejaculates, collected from dogs with optimal and suboptimal semen quality (optimal: normal morphology (NM) ≥ 80%, n = 9; suboptimal: NM between 60 and 79%, n = 9), were divided into two aliquots and sub...

The iSperm® is a portable device for semen analysis. This study aimed to investigate its correlation with a conventional computer-assisted sperm analyzer (ISAS®v1) for the assessment of semen concentration and kinematic parameters in dogs (n = 224). The intra-assay variability of both devices and their ability to estimate semen concentration at a f...

Bovine embryos are typically cultured at reduced oxygen tension to lower the impact of oxidative stress on embryo development. However, oocyte in vitro maturation (IVM) is performed at atmospheric oxygen tension since low oxygen during maturation has a negative impact on oocyte developmental competence. Lycopene, a carotenoid, acts as a powerful an...

Breed type and environmental factors such as breeding season may have a significant impact on neonatal morphometrics. We followed a total of 236 elective cesarean sections in Belgian Blue (BB) cows, from which neonatal calves were morphometrically assessed (in cm) within the first 72 h of delivery using a strictly standardized protocol. The effect...

Simple Summary Reproduction in small animals is an expanding research area, with focus on breeding improvement and clinical management of domestic carnivores. The aim of the present study was to conduct a bibliometric analysis of the literature of the last decade on small animal reproduction, to point out main sources, most prolific countries, and...