Among populations of the Miniopterus bats of western Palaearctic, intraspecific variation has not been well documented. Herein we investigate sexual and age variation of these populations using two approaches – linear and geometric morphometrics. We analysed Moroccan (M. maghrebesnis), western and eastern European (M. schreibersii), Levantine (M. schreibersii), and east-Afghanistani (M. cf. fuliginosus) specimens; variation was compared between sexes of the particular specimen sets of three above mentioned Miniopterus spp. and between four age cohorts of
M. schreibersii samples. The results showed in all examined population sets males to be generally larger in size than females, the exception being the east-European animals. Significatly the most divergent sexes were those from eastern Afghanistan, the Levant and eastern Europe. The differences found between sexes in as well as between examined population sets can
be attributed to different life histories and/or to food competition. Weak correlations between patterns of sexual dimorphism and the newly proposed western Palaearctic classification of the Miniopterus bats suggest only a limited contribution of sexual variation to morphological variation in general. Certain aspects of age variaton were found in all examined morphological characters except the non-metric traits, which in turn indicates the importance of these traits for identification of the particular taxon across age categories.
The direction and level of sexual size dimorphism (SSD) was examined in fire-bellied toads from the central Balkans. Samples were taken from 12 populations: three Bombina bombina, three B. variegata variegata and six B. variegata scabra populations. Intersexual variation of 20 morphometric characters was analysed. In addition, correspondence analysis of eight qualitative characters was performed. The results showed that, though body length had an inconsistent pattern of intersexual variation across taxa, other traits contributed to statistically significant level of SSD. The analysis on multivariate level revealed a highly significant effect of population in all three taxa, and significant effect of sex on character variation. Discriminant analysis confirmed a higher level of intersexual differences in B. variegata compared to B. bombina. Correspondence analysis showed that females and males were similar with respect to qualitative traits in all three taxa. At the univariate level, the most prominent features were: significant differences in tibia length in all three taxa, and highly significant differences in head width in B. bombina and in humerus length in B. v. scabra. These results are discussed with respect to specific reproductive behaviour and possible ecological differences between sexes.
The expression of sexually dimorphic phenotypes from a shared genome between males and females is a longstanding puzzle in evolutionary biology. Increasingly, research has made use of transcriptomic technology to examine the molecular basis of sexual dimorphism through gene expression studies, but even this level of detail misses the metabolic processes that ultimately link gene expression with the whole organism phenotype. We use metabolic profiling in Drosophila melanogaster to complete this missing step, with a view to examining variation in male and female metabolic profiles, or metabolomes, throughout development. We show that the metabolome varies considerably throughout larval, pupal and adult stages. We also find significant sexual dimorphism in the metabolome, although only in pupae and adults, and the extent of dimorphism increases throughout development. We compare this to transcriptomic data from the same population and find that the general pattern of increasing sex differences throughout development is mirrored in RNA expression. We discuss our results in terms of the usefulness of metabolic profiling in linking genotype and phenotype to more fully understand the basis of sexually dimorphic phenotypes., Fiona C. Ingleby, Edward H. Morrow., and Obsahuje bibliografii
Sexually dimorphic features of adult males and females of Soricidex dimorphus, a species unparalleled in its dimorphism by any described representative of the family Demodecidae, are compared by scanning electron microscopy. The account of sexual dimorphism in S. dimorphus is preceded by a review of sexually dimorphic features in other demodecid genera. Minute constituents of general morphology of demodecid mites such as claws, solenidia and spines of legs or palps, dorsal podosomal tubercles, and integumental slits and pores, part of which are reported and/or shown in scanning electron micrographs for the first time, are also receiving detailed attention.
For the evaluation of sexual dimorphism 739 red fox skulls (including 433 males and 306 females) from the Czech Republic were examined. The individuals younger than six months were excluded from the study of sexual dimorphism and the rest was divided into three age classes (individuals at the age of 6.5–12 months, 12.5–24 months and 24.5 months and older). Skull size differences between males and females were significant in all age classes. Males exceeded females in all dimensions with the exception of postorbital breadth, which was wider in females. Other skull shape differences between males and females were not confirmed. Age class including individuals 12.5–24 months old was the only, in which significant skull shape differences were found. We suppose that competition between males could play the major role in sexual dimorphism formation.
Morphological differences between female and male spined loaches belonging to five species from the Adriatic basin were examined. Besides the presence of the Canestrini scale and the length of the pectoral fins, sexual dimorphism is also visible in the position of the pectoral fins, as well as in the length of the pelvic fins. Both pectoral and pelvic fins are significantly longer in males than in females, whereas pectoral fins of females are located more anteriorly then in males. Differences in the length of pectoral and pelvic fins among species are also revealed. The role of the secondary sexual characters in males is probably connected with their special mating behaviour. Furthermore, a hypothesis that habitat conditions have greater impact on body dimensions of females than males is proposed.
Two chromosomal races of the house moue occur in central Tunisia: a standard type (2n = 40) and a Robertsonian race (2n = 22). Although contact between races is not restricted, hybrid populations are rare. Patterns of mate preference between wild mice of the two races suggest that, although incipient, this premating divergence could limit the number of crosses between races in nature. In this paper we compare sexual preference of laboratory-born mice and their parents caught as adults in the wild with the aim to assess whether the social context of development to adulthood could influence expression of preference. We predict that in the absence of such influence, parents and laboratory-born offspring should show a comparable pattern of preference. Results show that offspring preference is always lower than and not related to that of their parents. However, a significant pair effect exist leading us to group parents and offspring into three categories according to the parents' preference: homokaryotypic, heterokaryotypic, or dissimilar. Offspring exhibit a preference, which is consistent with that of their parents, only in two cases: male offspring of the standard race when both parents show a heterokaryotypic preference; all offspring when the homokaryotypic preference of fathers is high. Discrepancy between preferences of wild-caught mice and their laboratory-born progeny suggests that, here, preference may be partly influenced by social conditions experienced before and during adulthood.