BACKGROUND: Interspecific reproductive isolation is typically achieved by a combination of intrinsic and extrinsic barriers. Behavioural isolating barriers between sympatric, closely related species are often of primary importance and frequently aided by extrinsic factors causing spatial and temporal interspecific separation. Study systems with a severely limited role of extrinsic factors on reproductive isolation may provide valuable insights into how reproductive isolation between sympatric species is maintained. We used no-choice experimental set-up to study reproductive barriers between two closely related sympatric African killifish species, Nothobranchius furzeri and Nothobranchius orthonotus. These fish live in small temporary savannah pools and have complete spatial and temporal overlap in reproductive activities and share a similar ecology. PRINCIPAL FINDINGS: We found that the two species display largely incomplete and asymmetric reproductive isolation. Mating between N. furzeri males and N. orthonotus females was absent under standard experimental conditions and eggs were not viable when fish were forced to mate in a modified experimental setup. In contrast, male N. orthonotus indiscriminately mated with N. furzeri females, the eggs were viable, and offspring successfully hatched. Most spawnings, however, were achieved by male coercion and egg production and embryo survival were low. Behavioural asymmetry was likely facilitated by mating coercion from larger males of N. orthonotus and at relatively low cost to females. Interestingly, the direction of asymmetry was positively associated with asymmetry in post-mating reproductive barriers. SIGNIFICANCE: We showed that, in fish species with a promiscuous mating system and multiple matings each day, selection for strong mate preferences was relaxed. This effect was likely due to the small proportion of resources allocated to each single mating and the high potential cost to females from mating refusal. We highlight and discuss the fact that males of rarer species may often coercively mate with females of a related, more abundant species.

• MeSH
• Fundulidae fyziologie   MeSH
• rozmnožování fyziologie   MeSH
• sexuální chování zvířat fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Speciation may occur when the genomes of two populations accumulate genetic incompatibilities and/or chromosomal rearrangements that prevent inter-breeding in nature. Chromosome stability is critical for survival and faithful transmission of the genome, and hybridization can compromise this. However, the role of chromosomal stability on hybrid incompatibilities has rarely been tested in recently diverged populations. Here, we test for chromosomal instability in hybrids between nascent species, the 'dwarf' and 'normal' lake whitefish (Coregonus clupeaformis). We examined chromosomes in pure embryos, and healthy and malformed backcross embryos. While pure individuals displayed chromosome numbers corresponding to the expected diploid number (2n = 80), healthy backcrosses showed evidence of mitotic instability through an increased variance of chromosome numbers within an individual. In malformed backcrosses, extensive aneuploidy corresponding to multiples of the haploid number (1n = 40, 2n = 80, 3n = 120) was found, suggesting meiotic breakdown in their F1 parent. However, no detectable chromosome rearrangements between parental forms were identified. Genomic instability through aneuploidy thus appears to contribute to reproductive isolation between dwarf and normal lake whitefish, despite their very recent divergence (approx. 15-20 000 generations). Our data suggest that genetic incompatibilities may accumulate early during speciation and limit hybridization between nascent species.

• MeSH
• aneuploidie * MeSH
• chromozomální nestabilita MeSH
• embryo nesavčí abnormality   MeSH
• hybridizace genetická MeSH
• reprodukční izolace MeSH
• rozmnožování genetika   MeSH
• Salmonidae abnormality   embryologie   genetika   MeSH
• vznik druhů (genetika) MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Východisko. Mikrodelécie dlhého ramienka chromozómu Y patria k významným príčinám neobštrukčnej azoospermie a oligospermie. Cieľom tejto práce bolo zaviesť spoľahlivú molekulárne-genetickú metódu diagnostiky mikrodelécií chromozómu Y a zistiť zastúpenie jednotlivých typov mikrodelécií chromozómu Y u českých mužov so závažnými poruchami reprodukcie. Metódy a výsledky. Mikrodelécie chromozómu Y boli vyšetrované u 198 českých mužov s ťažkou poruchou reprodukcie so zníženým počtom spermií. Mikrodelécie chromozómu Y boli nájdené u 8/198 (4,0 %) vyšetrených mužov. Delécia v AZFc oblasti bola zistená v 62,5 % (5/8), kombinácia AZFc a AZFb delécie v 37,5 % (3/8) prípadov. Izolovaná delécia AZFb a ani delécia AZFa nebola nájdená. Závery. Určili sme zastúpenie jednotlivých typov mikrodelécií Y chromozómu u českých mužov s ťažkými poruchami reprodukcie. Bola zavedená štandardná molekulárne genetická diagnostika mikrodelécií chromozómu Y do rutinnej praxe.

Background. The Y chromosome microdeletions belong to the frequent genetical causes of male infertility. The aim of our studywas to introduce reliablemolecular genetic diagnosis of Ychromosomal microdeletions and to determine the prevalence of Y chromosomal microdeletions in Czech males with serious reproductive disorders. Methods and Results. The Ychromosomemicrodeletions were screened in 198Czech menwith serious reproductive disorders with decreased sperm count. The Y chromosome microdeletions were disclosed in 8/198 (4.0 %) examined males. The AZFc deletion type was revealed in 62,5 % (5/8) and the combined AZFc+b microdeletion in 37,5 % (3/8) of cases. Neither isolated AZFb nor AZFa microdeletion were found in any subject of the investigated group. Conclusions. Incidence of individual types of Y chromosomal microdeletions in Czech males with serious reproductive disorders was assessed. The standardisedmolecular genetic diagnosis ofYchromosomalmicrodeletions was introduced into the practice.

• MeSH
• asistovaná reprodukce MeSH
• chromozom Y genetika   MeSH
• chromozomální delece MeSH
• dospělí MeSH
• finanční podpora výzkumu jako téma MeSH
• genetické markery MeSH
• lidé MeSH
• mužská infertilita diagnóza   etiologie   MeSH
• polymerázová řetězová reakce MeSH
• spermatogeneze MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• přehledy MeSH
• srovnávací studie MeSH

• MeSH
• diploidie MeSH
• lidé MeSH
• opylení * MeSH
• polyploidie MeSH
• reprodukční izolace * MeSH
• tetraploidie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• komentáře MeSH

Studies of a hybrid zone between two house mouse subspecies (Mus musculus musculus and M. m. domesticus) along with studies using laboratory crosses reveal a large role for the X chromosome and multiple autosomal regions in reproductive isolation as a consequence of disrupted epistasis in hybrids. One limitation of previous work has been that most of the identified genomic regions have been large. The goal here is to detect and characterize precise genomic regions underlying reproductive isolation. We surveyed 1401 markers evenly spaced across the genome in 679 mice collected from two different transects. Comparisons between transects provide a means for identifying common patterns that likely reflect intrinsic incompatibilities. We used a genomic cline approach to identify patterns that correspond to epistasis. From both transects, we identified contiguous regions on the X chromosome in which markers were inferred to be involved in epistatic interactions. We then searched for autosomal regions showing the same patterns and found they constitute about 5% of autosomal markers. We discovered substantial overlap between these candidate regions underlying reproductive isolation and QTL for hybrid sterility identified in laboratory crosses. Analysis of gene content in these regions suggests a key role for several mechanisms, including the regulation of transcription, sexual conflict and sexual selection operating at both the postmating prezygotic and postzygotic stages of reproductive isolation. Taken together, these results indicate that speciation in two recently diverged (c. 0.5 Ma) house mouse subspecies is complex, involving many genes dispersed throughout the genome and associated with distinct functions.

• MeSH
• chromozom X genetika   MeSH
• genetická epistáze MeSH
• genetická variace MeSH
• hybridizace genetická MeSH
• jednonukleotidový polymorfismus MeSH
• lokus kvantitativního znaku MeSH
• myši genetika   MeSH
• reprodukční izolace MeSH
• sexuální výběr u zvířat MeSH
• vznik druhů (genetika) MeSH
• zvířata MeSH
• Check Tag
• myši genetika   MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

• MeSH
• ekotoxikologie MeSH
• infertilita MeSH
• rozmnožování MeSH
• techniky in vitro MeSH
• testy toxicity MeSH
• vystavení vlivu životního prostředí MeSH
• Publikační typ
• kongresy MeSH
• sborníky MeSH
• zprávy MeSH

• Konspekt
• Farmacie. Farmakologie
• NLK Obory
• toxikologie
• reprodukční lékařství

Moderní doba přinesla i do endokrinologie nové diagnostické a terapeutické postupy, změnil se přístup k celé řadě chorob a vývojových poruch. Exploze nových poznatků se projevuje zejména při vyšetření na subcelulární úrovni. Zkoumá se stavba a funkce různých receptorů a genů, tato problematika již přestala být futurologií. Přesto však zůstávají v medicíně oblasti, jimž až dosud není věnována náležitá pozornost. V endokrinologii dětského a adoles- centního věku je to například problematika reprodukce a budoucí fertility. Může se zdát, že tato oblast je dětskému věku vzdálená. Je však nutno si uvědomit, že některé poruchy reprodukce mají svůj počátek již v tomto období života. Obvykle se předpokládá, že otázky fertility bude řešit až lékař-specialista pro dospělé. Jsme přesvědčeni o tom, že uvedenou problematiku je naopak nutno řešit v rámci mezioborové spolupráce a v úzké návaznosti již od dětského věku. Cílem tohoto sdělení je podat přehled o endokrinních poruchách ve vztahu k poruchám reprodukce a nastínit možnosti spolupráce různých lékařských oborů od dětského věku po dospělost.

Modern era brought new diagnostic and therapeutic methods to endocrinology and changed the approach to many diseases and developmental disorders. Explosion of new findings brought about the possibility of examinations on subcellular level. Possibility to study structure and function of various genes is not any more the futurology. However, still in medicine romain a roas which are considered as less important. It is usually assumed that questions of fertility will be dealt by the specialist for adults. We suppose that the given problems should be well advised by an interdisciplinary co-operating team in the paediatric patients already. However, it should be recognised that some reproduction disorders have their origin in the early age. The aim of this paper is to give an overview on endocrine disorders in relation to reproduction impairments and to outline possibilities of co-operation between different specialist treating patients from childhood trough adulthood.

• MeSH
• diabetes mellitus 1. typu MeSH
• dítě MeSH
• dospělí MeSH
• finanční podpora výzkumu jako téma MeSH
• hyperandrogenismus MeSH
• hypogonadismus etiologie   genetika   terapie   MeSH
• hypopituitarismus etiologie   terapie   MeSH
• infertilita etiologie   MeSH
• kongenitální adrenální hyperplazie MeSH
• lidé MeSH
• mladiství MeSH
• reprodukční lékařství MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• přehledy MeSH

Spermadhesins are proteins containing a characteristic CUB domain, originally isolated from seminal plasma and ejaculated spermatozoa in domestic animals. Boar spermadhesins are multifunctional proteins exhibiting ligand-binding abilities with various endogenous ligands present in the male and female reproductive tracts and may play a role in the reproduction process. Porcine spermadhesins (AQN, AWN, PSP protein families) are secreted mainly by the seminal vesicles, but their mRNAs have been found also in the cauda epididymis and prostate. Unlike AQN and AWN spermadhesins, localization of porcine seminal plasma (PSP) proteins in the boar reproductive tract has not been completely resolved. This work has focused on PSP protein expression and localization in the boar reproductive organs and on spermatozoa. Using specific rabbit polyclonal antibodies (anti-PSP I and anti-PSP II), PSP I and PSP II proteins were immunodetected in tissue extracts and in secretory tissues of cauda epididymis, prostate, seminal vesicles and Cowper's glands on the blots and by an indirect immunofluorescence technique, respectively. Moreover, the ability of PSP proteins to bind to epididymal spermatozoa indicated their presence on cauda epididymal and ejaculated spermatozoa. Porcine seminal plasma proteins bind to the sperm surface at ejaculation and may modulate several aspects of sperm activity during reproduction. PSP proteins are produced not only by seminal vesicles and prostate, but also by epididymis. However, their prospective role in sperm epididymal maturation is not clear. Further characterization of seminal plasma protein forms expressed in the individual reproductive organs will help to understand their subsequent role in the reproduction process.

• MeSH
• financování organizované MeSH
• mužské pohlavní orgány cytologie   metabolismus   MeSH
• prasata MeSH
• proteiny semenné plazmy biosyntéza   MeSH
• regulace genové exprese fyziologie   MeSH
• rozmnožování fyziologie   MeSH
• sperma metabolismus   MeSH
• spermie cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH

The common bed bug Cimex lectularius, has been recently shown to constitute two host races, which are likely in the course of incipient speciation. The human-associated lineage splits from the ancestral bat-associated species deep in the history of modern humans, likely even prior to the Neolithic Period and establishment of the first permanent human settlements. Hybridization experiments between these two lineages show that post-mating reproductive barriers are incomplete due to local variation. As mating takes place in off-host refugia marked by aggregation semiochemicals, the present investigation tested the hypothesis that bed bugs use these semiochemicals to differentiate between refugia marked by bat- and human-associated bed bugs; this would constitute a pre-copulation isolation mechanism. The preference for lineage-specific odors was tested using artificial shelters conditioned by a group of either male or female bed bugs. Adult males were assayed individually in four-choice assays that included two clean unconditioned control shelters. In most assays, bed bugs preferred to rest in conditioned shelters, with no apparent fidelity to shelters conditioned by their specific lineage. However, 51 % of the bat-associated males preferred unconditioned shelters over female-conditioned shelters of either lineage. Thus, bed bugs show no preferences for lineage-specific shelters, strongly suggesting that semiochemicals associated with shelters alone do not function in reproductive isolation.

• MeSH
• biotest MeSH
• Chiroptera parazitologie   MeSH
• hybridizace genetická MeSH
• infestace ektoparazity parazitologie   veterinární   MeSH
• lidé MeSH
• odoranty analýza   MeSH
• rozmnožování MeSH
• štěnice klasifikace   genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Population divergence in geographic isolation is due to a combination of factors. Natural and sexual selection may be important in shaping patterns of population differentiation, a pattern referred to as 'isolation by adaptation' (IBA). IBA can be complementary to the well-known pattern of 'isolation by distance' (IBD), in which the divergence of closely related populations (via any evolutionary process) is associated with geographic isolation. The barn swallow Hirundo rustica complex comprises six closely related subspecies, where divergent sexual selection is associated with phenotypic differentiation among allopatric populations. To investigate the relative contributions of selection and geographic distance to genome-wide differentiation, we compared genotypic and phenotypic variation from 350 barn swallows sampled across eight populations (28 pairwise comparisons) from four different subspecies. We report a draft whole-genome sequence for H. rustica, to which we aligned a set of 9493 single nucleotide polymorphisms (SNPs). Using statistical approaches to control for spatial autocorrelation of phenotypic variables and geographic distance, we find that divergence in traits related to migratory behaviour and sexual signalling, as well as geographic distance, together explain over 70% of genome-wide divergence among populations. Controlling for IBD, we find 42% of genomewide divergence is attributable to IBA through pairwise differences in traits related to migratory behaviour and sexual signalling alone. By (i) combining these results with prior studies of how selection shapes morphological differentiation and (ii) accounting for spatial autocorrelation, we infer that morphological adaptation plays a large role in shaping population-level differentiation in this group of closely related populations.

• MeSH
• biologická evoluce * MeSH
• fenotyp MeSH
• genom MeSH
• populační genetika * MeSH
• reprodukční izolace MeSH
• selekce (genetika) * MeSH
• vlaštovkovití genetika   MeSH
• zeměpis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH