scholarly journals Female major histocompatibility complex type affects male testosterone levels and sperm number in the horse ( Equus caballus )

2015 ◽  
Vol 282 (1807) ◽  
pp. 20150407 ◽  
Author(s):  
D. Burger ◽  
G. Dolivo ◽  
E. Marti ◽  
H. Sieme ◽  
C. Wedekind

Odours of vertebrates often contain information about the major histocompatibility complex (MHC), and are used in kin recognition, mate choice or female investment in pregnancy. It is, however, still unclear whether MHC-linked signals can also affect male reproductive strategies. We used horses ( Equus caballus ) to study this question under experimental conditions. Twelve stallions were individually exposed either to an unfamiliar MHC-similar mare and then to an unfamiliar MHC-dissimilar mare, or vice versa. Each exposure lasted over a period of four weeks. Peripheral blood testosterone levels were determined weekly. Three ejaculates each were collected in the week after exposure to both mares (i.e. in the ninth week) to determine mean sperm number and sperm velocity. We found high testosterone levels when stallions were kept close to MHC-dissimilar mares and significantly lower ones when kept close to MHC-similar mares. Mean sperm number per ejaculate (but not sperm velocity) was positively correlated to mean testosterone levels and also affected by the order of presentation of mares: sperm numbers were higher if MHC-dissimilar mares were presented last than if MHC-similar mares were presented last. We conclude that MHC-linked signals influence testosterone secretion and semen characteristics, two indicators of male reproductive strategies.

Placenta ◽  
2018 ◽  
Vol 74 ◽  
pp. 36-46 ◽  
Author(s):  
A. Rapacz-Leonard ◽  
M. Leonard ◽  
M. Chmielewska-Krzesińska ◽  
K. Paździor-Czapula ◽  
T. Janowski

2016 ◽  
Vol 283 (1842) ◽  
pp. 20161966 ◽  
Author(s):  
J. W. G. Slade ◽  
M. J. Watson ◽  
T. R. Kelly ◽  
G. B. Gloor ◽  
M. A. Bernards ◽  
...  

In jawed vertebrates, genes of the major histocompatibility complex (MHC) play a key role in immunity by encoding cell-surface proteins that recognize and bind non-self antigens. High variability at MHC suggests that these loci may also function in social signalling such as mate choice and kin recognition. This requires that MHC genotype covaries with some perceptible phenotypic trait. In mammals and fish, MHC is signalled chemically through volatile and non-volatile peptide odour cues, facilitating MHC-dependent mate choice and other behaviours. In birds, despite evidence for MHC-dependent mating, candidate mechanisms for MHC signalling remain largely unexplored. However, feather preen wax has recently been implicated as a potential source of odour cues. We examined whether the chemical composition of preen wax correlates with MHC class IIβ genotypes of wild song sparrows ( Melospiza melodia ). Pairwise chemical distance reflected amino acid distance at MHC for male–female dyads, although not for same-sex dyads. Chemical diversity did not reflect MHC diversity. We used gas chromatography–mass spectrometry (GC-MS) to characterize preen wax compounds, and identified four wax esters that best reflect MHC similarity. Provided songbirds can detect variation in preen wax composition, this cue may allow individuals to assess MHC compatibility of potential mates.


1990 ◽  
Vol 64 (04) ◽  
pp. 564-568 ◽  
Author(s):  
Lloyd E Lippert ◽  
Lyman Mc A Fisher ◽  
Lawrence B Schook

SummaryApproximately 14% of transfused hemophiliacs develop an anti-factor VIII inhibitory antibody which specifically neutralizes factor VIII procoagulant activity. In this study an association of the major histocompatibility complex (MHC) with inhibitor antibody formation was evaluated by restriction fragment length polymorphism (RFLP) analysis using BamHI, EcoRI, HindII, PstI, PvuII and TaqI digested genomic DNA probed with DP beta, DQ alpha, DQ beta and DR beta class II MHC gene probes. The RFLP patterns for 16 non-inhibitor and 11 inhibitor hemophiliac patients were analyzed. These 24 enzyme:probe combinations generated 231 fragments. Fifteen (15) fragments associated with the inhibitor phenotype; odds ratios ranged from 5.1 to 45 and lower bounds of 95% confidence intervals were > 1.000 for all 15 fragments. Five (5) fragments associated with non-inhibitors, with odds ratios ranging from 6.4 to 51.7. This report establishes a MHC related genetic basis for the inhibitor phenotype. No statistically significant differences in the distribution of serologically defined HLA-DR phenotypes were observed between the inhibitor and non-inhibitor groups.


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