Rabbit oviductal glycoprotein 1 gene: Genomic organization polymorphism analysis and mRNA expression

Candidate genes associated with reproductive traits in rabbits

In the era of scientific advances and genetic progress, opportunities in the livestock sector are constantly growing. The application of molecular-based methods and approaches in farm animal breeding would accelerate and improve the expected results. The current work aims to comprehensively review the most important causative mutations in candidate genes that affect prolificacy traits in rabbits. Rabbits are a source of excellent-tasting meat that is high in protein and low in fat. Their early maturity and intensive growth are highly valued all over the world. However, improving reproductive traits and prolificacy in rabbits could be very tricky with traditional selection. Therefore, traditional breeding programs need new methods based on contemporary discoveries in molecular biology and genetics because of the complexity of the selection process. The study and implementation of genetic markers related to production in rabbits will help to create populations with specific productive traits that will produce the desired results in an extremely short time. Many studies worldwide showed an association between different genes and productive traits in rabbits. The study of these polymorphisms and their effects could be useful for molecular-oriented breeding, particularly marker-assisted selection programs in rabbit breeding.

A Comparative View on the Oviductal Environment during the Periconception Period

The oviduct plays important roles in reproductive events: sperm reservoir formation, final gamete maturation, fertilization and early embryo development. It is well known that the oviductal environment affects gametes and embryos and, ultimately, the health of offspring, so that in vivo embryos are better in terms of morphology, cryotolerance, pregnancy rates or epigenetic profile than those obtained in vitro. The deciphering of embryo-maternal interaction in the oviduct may provide a better understanding of the embryo needs during the periconception period to improve reproductive efficiency. Here, we perform a comparative analysis among species of oviductal gene expression related to embryonic development during its journey through the oviduct, as described to date. Cross-talk communication between the oviduct environment and embryo will be studied by analyses of the secreted or exosomal proteins of the oviduct and the presence of receptors in the membrane of the embryo blastomeres. Finally, we review the data that are available to date on the expression and characterization of the most abundant protein in the oviduct, oviductin (OVGP1), highlighting its fundamental role in fertilization and embryonic development.

Congenital Midline Cervical Cleft: First Report and Genetic Analysis of Two Related Patients

OBJECTIVES

Congenital midline cervical cleft (CMCC) is a rare congenital anterior neck anatomical anomaly. We present the case of two related patients (grandchild and maternal grandmother) who were both born with a congenital midline cervical cleft along with genetic analysis.

METHODS

Clinical examination of both patients and surgical excision of the grandchild was performed. Genetic analysis with exome sequencing (ES) was conducted for both patients.

RESULTS

Genetic analysis with exome sequencing (ES) revealed apparently novel single nucleotide variants in 66 genes present in both proband and grandmother. Five of these variants are predicted to cause frameshifting in the coding region of the respective genes and truncated proteins (OVGP1, TYW1B, ZAN, SSPO, FOLR3). Two of these genes (TYW1B and SSPO) have homozygous indel mutations in both patients.

CONCLUSIONS

To our knowledge, this is the first case of two related patients with a congenital midline cervical cleft. The results of our genetic analysis reveal potential relevance to CMCC development.

Structural and functional characterization of buffalo oviduct-specific glycoprotein (OVGP1) expressed during estrous cycle

Oviduct-specific glycoprotein (OVGP1) is a high molecular weight chitinase-like protein belonging to GH18 family. It is secreted by non-ciliated epithelial cells of oviduct during estrous cycle providing an essential milieu for fertilization and embryo development. The present study reports the characterization of buffalo OVGP1 through structural modeling, carbohydrate-binding properties and evolutionary analysis. Structural model displayed the typical fold of GH18 family members till the boundary of chitinase-like domain further consisting of a large (β/α)8 TIM barrel sub-domain and a small (α+β) sub-domain. Two critical catalytic residues were found substituted in the catalytic centre (Asp to Phe118, Glu to Leu120) compared with the active chitinase. The carbohydrate-binding groove in TIM barrel was lined with various conserved aromatic residues. Molecular docking with different sugars revealed the involvement of various residues in hydrogen-bonding and non-bonded contacts. Most of the substrate-binding residues were conserved except for a few replacements (Ser13, Lys48, Asp49, Pro50, Asp167, Glu199, Gln272 and Phe275) in comparison with other GH18 members. The residues Trp10, Trp79, Asn80, Gln272, Phe275 and Trp334 were involved in recognition of all six ligands. The α+β sub-domain participated in sugar-binding through Thr270, Gln272, Tyr242 and Phe275. The binding assays revealed significant sugar-binding with purified native and recombinant OVGP1. Phylogenetic analysis revealed that OVGP1 was closely related to AMCases followed by other CLPs and evolution of OVGP1 occurred through several gene duplications. This is the first study describing the structural characteristics of OVGP1 that will further help to understand its interaction with gametes to perform crucial reproductive functions.

Treatment evaluation of Wharton's jelly-derived mesenchymal stem cells using a chronic salpingitis model: an animal experiment

Background

The present study was conducted to evaluate new methods to repair the reproductive function of the oviduct, thereby allowing gametes to combine and grow in vivo under natural circumstances.

Methods

Sixty pathogen-free female New Zealand rabbits were divided into three groups: a wild-type group, an untreated control group, and a treatment group. Disposable sterile newborn sputum suction tubes were inserted into the urogenital tract to instill an Escherichia coli suspension into the uterine cavity to establish the chronic salpingitis model. Wharton’s jelly-derived mesenchymal stem cells (WJMSCs) or normal saline were used to treat this infection via different methods. The therapeutic effect was assessed by evaluating morphology, inflammatory factors, proteinology, and pregnancy outcomes.

Results

Oviducts of New Zealand rabbits in the untreated control group showed structural failure and abnormal supermicrostructure of epithelial cells. WJMSCs could partially repair the structure and supermicrostructure of the tubal epithelium. The concentration of tumor necrosis factor (TNF)-α in the untreated control group was significantly higher than that in the wild-type group (P = 0.015). The concentration of TNF-α in the local treatment group was significantly lower than that in the untreated control group (P = 0.011). The expression of oviductal glycoprotein (OVGP) and OVGP mRNA in the wild-type group was significantly higher than those in the untreated control group (P = 0.024 and P = 0.013, respectively). The litter size of the treatment group was 2 ± 2.39 kits, which was higher than that of the untreated control group (P = 0.035).

Conclusion

Chronic inflammation can destroy the structure of the oviduct and the supermicrostructure of epithelial cells as well as leading to infertility. WJMSC transplantation therapy in rabbits with chronic salpingitis partially restored fertility. WJMSCs also repaired the structure of the tubal epithelium subjected to chronic inflammation, decreased the level of inflammatory factors, and partially restored the secretion level of OVGP.

Sequence analysis of feline oviductin and its expression during the estrous cycle in the domestic cat (Felis catus)

Oviductins belong to a family of oviduct-specific glycoproteins believed to play an important role in fertilization and/or early embryonic development. Oviductin cDNA between species is highly conserved and shares 58% to 98% similarity in the deduced amino acid sequences. Our objective in this study was to sequence the full open reading frame of the feline oviductin and to examine its expression during the estrous cycle on both mRNA and protein level. The obtained cDNA containing the full open reading frame was determined to be 1677 nucleotides coding for a deduced protein of 558 amino acids. Identities between species range from 74% (mouse) to 80% (human, baboon, and rhesus) within the N-terminal protein region. Major differences were localized in the carboxy terminal region, which corresponds to exon 11 of the gene. Feline oviductin contained one putative N-linked glycosylation site, six O-linked glycosylation sites, a potential heparin binding site, and two cholesterol recognition and/or interaction amino acid consensus (CRAC) domains. Oviductin expression was analyzed by real time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. Both approaches revealed an estrous cycle-dependent expression in the ampulla and isthmus. Quantitative PCR showed highest oviductin mRNA copy numbers in the early and late follicular stage and reduced mRNA expression during all other stages. With the exception of the early follicular stage, feline oviductin mRNA abundance was not significantly different in the oviductal segments ampulla and isthmus. A prominent immunolabeling was seen in the early and late follicular stage which disappeared after ovulation, indicating a function of the protein during sperm storage and fertilization.

Purification, sequence characterization and effect of goat oviduct-specific glycoprotein on in vitro embryo development

Oviduct-specific glycoprotein (oviductin) plays an important role during fertilization and early embryonic development. The oviductin cDNA was successfully cloned and sequenced in goat, which possessed an open reading frame of 1620 nucleotides representing 539 amino acids. Predicted amino acid sequence showed very high identity with sheep (97%) followed by cow (94%), porcine (77%), hamster (69%), human (66%), rabbit (65%), mouse (64%) and baboon (62%). The bioinformatics analysis of the sequences revealed the presence of a signal sequence of 21 amino acids, one potential N-linked glycosylation site at position 402, 21 potential O-linked glycosylation sites and 36 potential phosphorylation sites. The native oviductin was purified from the oviductal tissue, which showed three distinct bands on SDS-PAGE and western blot (MW ~60-95 kDa). The predicted molecular weight of goat oviductin was 57.5 kDa, calculated from the amino acid sequences. The observed higher molecular weight has been attributed to the presence of large number of potential O-linked glycosylation sites. The lower concentration (10 μg/mL) of oviductin increased the cleavage rate, morula and blastocyst yield significantly (P < 0.05) as compared to higher concentration (100 μg/mL). Goat oviductin retarded the activity of pronase (0.1%) on zona solubility of oocytes significantly (P < 0.01).

Oviductal secretions: will they be key factors for the future ARTs?

A variety of evolutionary processes has led to the development of different organs to ensure that internal fertilization occur successfully. Fallopian tubes are a particularly interesting example of such organs. Some of the key events during fertilization and early embryo development occur in the oviduct. Knowledge of the different components described in the oviduct is extensive. Oviductal components include hormones, growth factors and their receptors that have important roles in the physiology of the oviduct and embryo development. Other oviductal factors protect the gamete and the embryos against oxidative stress and pathogens. Different proteins and enzymes are present in the oviductal fluid and have the ability to interact with the oocyte and the sperm before the fertilization occurs. Of special interest is the oviduct-specific glycoprotein (OVGP1), a glycoprotein that is conserved in different mammals, and its association with the zona pellucida (ZP). Interaction of the oocyte with oviductal secretions leads us to emphasize the concept of 'ZP maturation' within the oviduct. The ZP changes produced in the oviduct result in an increased efficiency of the in vitro fertilization technique in some animal models, contributing in particular to the control of polyspermy and suggesting that a similar role could be played by oviductal factors in human beings. Finally, attention should be given to the presence in the oviductal fluid of several embryotrophic factors and their importance in relation to the in vivo versus in vitro developmental ability of the embryos.

Investigation of the oviductal glycoprotein 1 (OVGP1) gene associated with embryo survival and development in the rabbit

An association study was performed in rabbits between early embryo survival and development, and the nonconservative SNP 12944C>G located in exon 11 and the triallellic microsatellite [(GT)(15)T(G)(5), (GT)(14)T(G)(5), and (GT)(11)T(G)(7))] located in the promoter region of the oviductal glycoprotein 1 (OVGP1) gene. We analyzed an F(2) cross of 2 lines of rabbits divergently selected for uterine capacity. A total of 172 and 159 females were slaughtered at 48 and 72 h of gestation, respectively, to determine whether OVGP1 influences ovulation rate, fertilization rate, early embryo survival, and embryonic stage of development. The results of the SNP indicated that all genotypes showed similar early embryo survival and a similar embryonic stage of development at 48 h of gestation. However, at 72 h of gestation, the GG genotype showed greater early embryo survival than the CC genotype (0.56 embryos) and their embryos presented less embryonic development. Analysis of the microsatellite was performed to ascertain the presence or absence of the allele (GT)(14)T(G)(5). At both stages of gestation, the (GT)(14)T(G)(5)/(GT)(14)T(G)(5) genotype showed greater early embryo survival (0.94 and 1.54 embryos at 48 and 72 h of gestation, respectively) and less embryonic development than the homozygous genotypes without the allele (GT)(14)T(G)(5).