Mapping of bovine FcgammaR (FCGR) genes by sperm typing allows extended use of human map information

Soluble Fibrinogen-like protein 2 plays a role in varicocele induced male infertility

Varicocele is the most common cause of male infertility. Several theories have been proposed to explain how varicocele induces infertility. The role of epididymis in male infertility is not fully well established. Fibrinogen-like protein 2 is one of serine proteases and is a potent coagulant in membranous form and immune-modulator in soluble form (sFGL-2) and expressed in the epididymis. There are no previous reports about its possible role in varicocele. This case-controlled study aimed to evaluate the seminal level of sFGL-2 in infertile men with varicocele and in men with idiopathic infertility. This study included 85 participants divided into three groups; 25 normal fertile men, 30 infertile men with varicocele and 30 infertile men of idiopathic cause. Clinical examination, Doppler ultrasound, semen analysis and measurement of seminal level of sFGL-2 were done to all participants. Seminal level of sFGL-2 was significantly elevated in infertile than normal fertile men. Seminal level of sFGL-2 showed negative correlations with sperm concentration, motility and normal morphology. Seminal level of sFGL-2 had a positive correlation with seminal liquefaction time. This study concluded that seminal level of sFGL-2 is increased in infertile men with idiopathic cause and with varicocele induced infertility and affects seminal liquefaction.

Fc receptors in livestock species

Many of the receptors for the Fc domain of immunoglobulins in cattle, sheep, pigs and horses have been cloned and characterized recently. This review summarises recent developments and relates them to the current understanding of the primary structure, cellular specificity and binding properties of Fc receptors (FcRs). Although there is an obvious overall similarity to their human and mouse counterparts, some Fc receptors in domestic animals are unusual, perhaps most notably the bovine Fcgamma2R, which although related to other mammalian FcgammaRs, belongs to a novel gene family and the porcine FcgammaRIIIA, which associates with a molecule that contains significant homology to the cathelin family of antimicrobial proteins. Accumulating data suggest the possibility of a different role for the FcRn in ruminants, which may secrete IgG onto the mucosal surfaces, rather than absorbing it, as was suggested by mouse studies. These differences may be linked to the diversity of immunoglobulin classes in different mammalian species, and may contribute to different immune functions. The observations made so far emphasize the importance of elucidating and analyzing the roles of these molecules within the immune system of each host animal, rather than inferring roles from conclusions made in human and mouse studies. A better understanding of Fc receptor expression on immune effector cells should help in developing new immunization protocols, while knowledge of the Fc receptors involved in immunoglobulin transport, especially in the mammary gland, may help to develop new products which could be used not only for veterinary purposes but perhaps also for human therapy.

Molecular cloning and identification of full-length cDNA encoding high affinity Fc receptor for bovine IgG (Fc gamma RI)

The receptor I for the Fc region of immunoglobulin G (Fc gamma RI) is a member of the Ig superfamily with a high affinity, and it mediates antibody-dependent cellular cytotoxicity and immune complex clearance. In this study, a cDNA encoding the bovine Fc gamma RI was cloned. The full-length cDNA sequence is 1050 bp long with a short 5'- and long 3'-untranslated end regions, which codes for 349 amino acids and contains a signal peptide, an extracellular region with three Ig-like domains, and transmembrane and intracytoplasmic domains. Five potential N-linked glycosylation sites are recognized in this sequence. Compared with the sequences of human and mouse Fc gamma RI, the homologies of nucleotide sequences are 80 and 69% and homologies of deduced amino acid sequences are 66 and 55%, respectively. It is shown that the sequences of the monomeric IgG binding domain in these three species of Fc gamma RI are highly conserved.

Bovine FcgammaRIII with a single extracellular domain

The full length of gene encoding Fc receptor types III for bovine immunoglobulin G (boFcgammaRIII, CD16) was obtained with PCR from the c DNA library of bovine alveolar macrophages. Through molecular cloning and sequencing it is shown that the coding gene has 507 bp and codes for 168 amino acids. There are signal peptide, transmembrane spanning domain and three potential N-linked glycosylation sites in the sequence. Compared with the boFcgammaRIII cDNA sequence cloned by Collins et al, it deletes 82 amino acids and has only one extracellular domain. It is suggested that this cDNA fragment is a special form of the gene structure of bovine FcgammaRIIIA (CD16-II).

Evidence for heterogeneity in recombination in the human pseudoautosomal region: high resolution analysis by sperm typing and radiation-hybrid mapping

Accurate genetic and physical maps for the human pseudoautosomal region were constructed by use of sperm typing and high-resolution radiation-hybrid mapping. PCR analysis of 1,912 sperm was done with a manual, single-sperm isolation method. Data on four donors show highly significant linkage heterogeneity among individuals. The most significant difference was observed in a marker interval located in the middle of the Xp/Yp pseudoautosomal region, where one donor showed a particularly high recombination fraction. Longitudinal models were fitted to the data to test whether linkage heterogeneity among donors was significant for multiple intervals across the region. The results indicated that increased recombination in particular individuals and regions is compensated for by reduced recombination in neighboring intervals. To investigate correspondence between physical and genetic distances within the region, we constructed a high-resolution radiation-hybrid map containing 29 markers. The recombination fraction per unit of physical distance varies between regions ranging from 13- to 70-fold greater than the genome-average rate.

High-resolution gametic map of the sheep callipyge region: linkage heterogeneity among rams detected by sperm typing

The callipyge locus (CLPG) causing muscular hypertrophy in domestic sheep has previously been mapped to the distal part of ovine chromosome 18. In this study, an accurate multipoint linkage map consisting of six microsatellite markers in this chromosomal region was constructed based on the analysis of 1145 single sperm cells. The best supported order of markers was OARHH47-ILSTS54-MCM38-CSSM18-IDVGA30-BM S1561. The log odds against the second most likely order, which has a reversal of the closely linked markers CSSM18 and IDVGA30, was 5.026. Sperm typing can be used to examine a large number of meioses in single individuals, and therefore, was exploited to study individual variability of recombination rate in rams of different callipyge genotypes. The results revealed statistically significant linkage heterogeneity among rams (P < 0.05) for marker interval OARHH47-CSSM18, with individual recombination fractions varying from 0.209 to 0.357.

Characterisation of bovine peroxisome proliferator-activated receptors gamma 1 and gamma 2: genetic mapping and differential expression of the two isoforms

In this report we describe the isolation and characterisation of the cDNAs encoding two isoforms of peroxisome proliferator-activated receptor gamma (PPAR gamma), gamma 1 and gamma 2, in cattle. The cDNA sequences show strong conservation with the corresponding sequences reported in other species. The distribution of PPAR gamma mRNAs in various bovine tissues was investigated using Northern blot analysis. The highest expression was detected in adipose tissue with about equal amounts of the both transcripts while a differential expression was found in other tissues investigated. PPAR gamma 1 was expressed at relatively high levels in bovine spleen and lung and to a lower extent in ovary, mammary gland, and small intestine. The amount of PPAR gamma 2 was apparently lower than that of PPAR gamma 1 in spleen, lung, and ovary. These results indicate a modulation of tissue distribution for the two transcripts in cattle. Using genetic linkage analysis we have also assigned the PPAR gamma gene to bovine chromosome 22.