Study Of Reproductive Biology Research Articles

Sexual Size Dimorphism in Eastern Slow-Worm ( Anguis fragilis colchica , Reptilia: Anguidae)

The direction and magnitude of inter-sexual differences in body and head size in one eastern slow-worm ( A. f. colchica ) population were investigated. We compared morphological measures of 92 male and 127 female adult A. f. colchica from a single population. In line with our expectations, we found that females were generally larger, but males had larger relative head size. At similar growth rate a disproportionate increase of head size in males and respectively of body size in females are pointed. The sexual difference in relative head size increased with the size (a proxy for age) of the animals. Our results fits well to the general theory, especially when studies of the reproductive biology of the species — reporting vigorous male-male combats, the presence of copulatory bites, and showing that female fecundity is size dependent — is taken into account. However, considering this generalist species, another common hypothesis suspecting dietary divergence between sexes behind sexual differences in relative head size is not likely to represent a strong evolutionary pressure in this case.

Isolation and Characterization of Mesenchymal Stem Cells from Amniotic Fluid and Chorionic Villi

Isolation and Characterization of Mesenchymal Stem Cells from Amniotic Fluid and Chorionic Villi

Detection and analysis of endogenous badnaviruses in the New Zealand flora

Badnaviruses and their host-integrated DNA occur in tropical crops and a few northern temperate species. Following the discovery of a badnavirus on a subantarctic island with floristic links to New Zealand, we postulated that badnaviruses exist in the New Zealand flora. Badnavirus reverse transcriptase (RT) sequences consist of variable regions flanked by highly conserved regions. This study used RT sequences to detect and characterize badnavirus sequences in the New Zealand flora and to investigate their utility for the study of broader aspects of plant biology. Molecular diversity of RT sequences was analysed using polymerase chain reaction and denaturing gradient gel electrophoresis (DGGE). In a study of the genus Melicytus, internal transcribed spacer (ITS) sequences were compared with the RT data. No freely replicating badnaviruses were detected but more than half of the species (37/60) contained RT sequences. Phylogenetic analysis of 21 RT sequences formed monophyletic groups distinct from other species and from badnaviruses. No frameshift mutations occurred in any of the sequences translated in silico. More detailed study of the genus Melicytus indicated broader applications for our approach. Analysis of RT sequences revealed the presence of a previously unrecognized species (confirmed using ITS). Inheritance of DGGE profiles by Melicytus ramiflorus seedlings suggested that this species may undergo apomixis. The presence of integrated badnavirus sequences in a wide range of taxa from this Southern Hemisphere flora indicates that these sequences may be common in many temperate regions. Potential to activate viruses from these sequences should be considered when placing these species in tissue culture or under other forms of abiotic or genomic stress. Analysis of endogenous RT sequences shows potential for the study of systematics, phylogenetics and plant reproductive biology.

An integrated approach for the conservation of threatened plants: The case of Arabis kennedyae (Brassicaceae)

The aim of this paper is to propose an integrated approach (including population and habitat monitoring and the study of reproductive biology and genetic diversity) for the comprehensive study of threatened plants, for which conservation measures are imperative. We applied this model to the plant species Arabis kennedyae which is classified as endangered according to the IUCN criteria. The current population of the species consists of three small subpopulations (AR1, AR2, and AR3) at three locations. Population size was characterized by considerable annual fluctuations. The distribution pattern of the plant followed habitat availability. Relative Reproductive Success remained stable but moderate. Germination of dormant seeds was promoted by light and was optimal at 15 and 20 °C. Genetic analysis showed low interpopulation variability and detected two groups: haplotype I (AR1 and AR3) and haplotype II (AR2), which may represent two altitudinal ecotypes. The direct threats identified were related to recreation activities, road construction and fire. The subpopulations of the plant are regulated by density and depend on fecundity and on the soil seedbank while their persistence depends mainly on habitat availability. Low genetic diversity combined with small population size and a possible reduction in fitness suggest increased susceptibility to loss of genetic variation. The overall results suggest that ex situ conservation in a seed bank, and in situ conservation in the form of population restoration, are suitable conservation measures and the study of the different aspects of the species’ biology has provided the data required for their implementation.

Biologia floral, reprodutiva e propagação vegetativa de baunilha

Vanilla chamissonis is a species of orchid naturally occurring in the coastal strips of the state of Sao Paulo (Brazil), with high economic interest. However, sustainable management of natural stands aiming for commercial production of fruit is not put into practice. This study aims to describe some aspects of the floral biology, reproductive biology and vegetative propagation of natural stands of Vanilla chamissonis, aiming to generate information for its sustainable management. For studies of floral biology, the anthesis and senescence of flowers in daytime and nighttime periods, as well as pollinators, were monitored. For studies of reproductive biology, the following treatments were examined: T1-control (no intervention), T2-manual self-pollination/induced autogamy, T3-artificial cross-pollination/induced allogamy, T4-spontaneous self-pollination/autogamy, and T5-natural cross-pollination/allogamy. For studies of vegetative propagation, the lower portion of the cuttings was treated with indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA), both applied in paste at 3,000 mg L-1. Sustainable management of vanilla has the required attributes to application by the local community. Direct observation of flowers from anthesis until senescence was adequate, but it was not possible to determine the agents responsible for pollination. Cross-pollination is the most appropriate for management aiming for the commercial production of fruit. The use of IBA resulted in the greatest number of terrestrial roots.

A transcriptome analysis of mitten crab testes (Eriocheir sinensis)

The identification of expressed genes involved in sexual precocity of the mitten crab (Eriocheir sinensis) is critical for a better understanding of its reproductive development. To this end, we constructed a cDNA library from the rapid developmental stage of testis of E. sinensis and sequenced 3,388 randomly picked clones. After processing, 2,990 high-quality expressed sequence tags (ESTs) were clustered into 2,415 unigenes including 307 contigs and 2,108 singlets, which were then compared to the NCBI non-redundant (nr) protein and nucleotide (nt) database for annotation with Blastx and Blastn, respectively. After further analysis, 922 unigenes were obtained with concrete annotations and 30 unigenes were found to have functions possibly related to the process of reproduction in male crabs – six transcripts relevant to spermatogenesis (especially Cyclin K and RecA homolog DMC1), two transcripts involved in nuclear protein transformation, two heat-shock protein genes, eleven transcription factor genes (a series of zinc-finger proteins), and nine cytoskeleton protein-related genes. Our results, besides providing valuable information related to crustacean reproduction, can also serve as a base for future studies of reproductive and developmental biology.

Sequence analysis of genomic DNA (680 Mb) by GS-FLX-Titanium sequencer in the monogonont rotifer, Brachionus ibericus

The monogonont rotifer, Brachionus ibericus (S type), is considered to be a promising model species for developmental biology, evolution, and environmental genomics. In an attempt to accelerate the molecular understanding of B. ibericus, we sequenced 680.5 Mb of genomic DNA using the genome sequencer GS-FLX-Titanium. We obtained 2,062,621 reads (average read length 329.9 bp) and 145,418 contigs (total contigs length 125.7 Mb) after excluding small reads (less than 200 bp) from the assembly, and finally obtained 10,133 unigenes (E value ≤ 9.00E−04) after non-redundant (NR) BLAST search. In this article, we summarize the genomic DNA sequences of B. ibericus and discuss their potential use in the study of reproductive biology, endocrinology, environmental genomics, and ecotoxicological studies, and for providing insight into the genetic basis of mechanisms such as egg formation, antioxidant stress defense, and xenobiotic metabolism.

Long‐term proliferation and characterization of human spermatogonial stem cells obtained from obstructive and non‐obstructive azoospermia under exogenous feeder‐free culture conditions

The aim of the present study was to improve efficiency of isolation and to optimize proliferative potential of human spermatogonial stem cells (SSCs) obtained from obstructive azoospermic (OA) and non-obstructive azoospermic (NOA) patients, and further, to characterize these cells for potential use in infertility treatment or study of reproductive biology. We have applied a cell-sorting method, using collagen and magnetic activated cell separation to overcome obstacles, developing a collection system, and simple long-term proliferation system, that yields large numbers of high-purity SSCs from obstructive OA and NOA patients. SSCs derived from OA and NOA patients proliferated and maintained their characteristics for more than 12 passages (>6 months) in vitro. Moreover, the population of cells positive for the SSC-specific markers GFRalpha-1 and integrin alpha6, increased to more than 80% at passage 8. These finding may support the idea that in vitro propagation of SSCs could be a useful tool for infertility treatment and study of reproductive biology.

In vitro derivation of germ cells from embryonic stem cells

Embryonic stem cells (ESCs) have the potential to differentiate into cells of all tissue types, as demonstrated by their capability to contribute to the development of all germ layers in chimeras and to form teratomas. Of interest, however, is the lack of evidence of gametogenic gonadal tissues within teratomas, such as testicular tubules or follicles. Although this may reflect the fact that in vivo germ cell development and subsequent gametogenesis are complex biological processes, the generation of putative primordial germ cells (PGCs) has been reported during the differentiation of mouse and human ESCs in in vitro systems. In addition, mouse ESCs can even lead to the development of putative gametes, but the efficiency of this process needs to be improved and the functionality of the gametes remains to be proven. Interest in the generation of fully functional gametes from ESCs lies in an experimental model fundamental to the study of reproductive biology, a potential unlimited source of oocytes as a reprogramming bioreactor, and perhaps even in therapeutic applications to overcome human reproductive problems.

Low level of extrapair parentage in wild zebra finches

The captive zebra finch, Taeniopygia guttata, has become one of the key vertebrate model systems for studying a range of behavioural, physiological and neurological phenomena. In particular, this species has played a key role in developing our understanding of sexual selection and sperm competition. In contrast with the large number of studies using domesticated zebra finches, relatively few studies have focused on free-living populations of wild zebra finches. Investigating the incidence of extrapair paternity in zebra finches in the Australian desert, we found a very low level; 1.7% of 316 offspring from four of 80 broods fathered outside the pair bond. These numbers contrast with the high levels of extrapair paternity observed in domesticated aviary populations, and suggest a low level of sperm competition and sexual selection in natural populations. Our finding of such a low rate of extrapair paternity in the wild zebra finch suggests that it is one of the most genetically monogamous of all passerine species and that has important implications for future studies of this model organism in studies of sexual selection and reproductive biology. In addition, we found that 5.4% of 316 offspring were not related to either putative parent and hatched from eggs that had been dumped by intraspecific brood parasites.

The progamic phase of an early-divergent angiosperm, Annona cherimola (Annonaceae).

Background and AimsRecent studies of reproductive biology in ancient angiosperm lineages are beginning to shed light on the early evolution of flowering plants, but comparative studies are restricted by fragmented and meagre species representation in these angiosperm clades. In the present study, the progamic phase, from pollination to fertilization, is characterized in Annona cherimola, which is a member of the Annonaceae, the largest extant family among early-divergent angiosperms. Beside interest due to its phylogenetic position, this species is also an ancient crop with a clear niche for expansion in subtropical climates.MethodsThe kinetics of the reproductive process was established following controlled pollinations and sequential fixation. Gynoecium anatomy, pollen tube pathway, embryo sac and early post-fertilization events were characterized histochemically.Key ResultsA plesiomorphic gynoecium with a semi-open carpel shows a continuous secretory papillar surface along the carpel margins, which run from the stigma down to the obturator in the ovary. The pollen grains germinate in the stigma and compete in the stigma-style interface to reach the narrow secretory area that lines the margins of the semi-open stylar canal and is able to host just one to three pollen tubes. The embryo sac has eight nuclei and is well provisioned with large starch grains that are used during early cellular endosperm development.ConclusionsA plesiomorphic simple gynoecium hosts a simple pollen–pistil interaction, based on a support–control system of pollen tube growth. Support is provided through basipetal secretory activity in the cells that line the pollen tube pathway. Spatial constraints, favouring pollen tube competition, are mediated by a dramatic reduction in the secretory surface available for pollen tube growth at the stigma–style interface. This extramural pollen tube competition contrasts with the intrastylar competition predominant in more recently derived lineages of angiosperms.

Self-incompatibility and myophily in Octomeria (Orchidaceae, Pleurothallidinae) species

Pleurothallidinae (ca. 4,000 spp.) is the largest myophilous group in Orchidaceae. Recently three self-compatible bird-pollinated genera were included at the base of the group, while Octomeria (plus Brachionidium) is the sister group to the remaining subtribe in the former circumscription. Studies of reproductive biology of three Octomeria species were carried out to determine the occurrence of myophily and self-incompatibility in the genus, to help trace the evolution of these characteristics in the subtribe. The three species showed a strong self-incompatibility and are intercompatible. Octomeria crassifolia and O. grandiflora are pollinated by Sciaridae (Diptera) species, presenting high specificity. These results indicate that both self-incompatibility and myophily are basal characteristics in the former delimitation of the Pleurothallidinae and possibly have been kept in the derived lineages, representing biological synapomorphies of the group.

Reproductive biology and cytology of Hypericum brasiliense Choisy (Hypericaceae)

This is the first study of reproductive biology and cytology carried out with Hypericum brasiliense, a species with medicinal properties and potential agronomic interest. Three populations of H. brasiliense collected at Southeastern Brazil were studied. The results indicate that H. brasiliense is preferentially allogamous, self-compatible, facultative apomitic and anemophilous. Male sterility was observed in about 50% of individuals from the three populations. Anatomical studies evidenced structural abnormalities in anthers of male sterile flowers, showing enlarged tapetal cells and thick secretion deposits on the tapetal cell surfaces that may cause nutritional deficit for pollen mother cells. In cytogenetic studies several haploid chromosome numbers were observed like n = 4, 8, 9, 11, 16 and 17, including the presence of multivalents and micronuclei in tetrads, indicating the occurrence of abnormalities in the meiotic process of H. brasiliense. Despite these meiotic abnormalities the pollen viability and in vitro pollen germination rate observed in fertile flowers may be considered high. The diploid chromosome number 2n = 16 was observed, and the chromosomes in metaphase were small and similar. Fluorochrome staining techniques using DAPI and CMA3 were applied, with no positive bands observed.

Reproductive biology of Cyrtopodium punctatum in situ: implications for conservation of an endangered Florida orchid

Abstract Cyrtopodium punctatum (Linnaeus) Lindley is an endangered epiphytic orchid restricted in the USA to southern Florida. This species has been extensively collected from the wild since the early 1900s, and today only a few plants remain in protected areas. As part of a conservation plan, a reproductive biology study was conducted to better understand the ecology of this species in Florida. Cyrtopodium punctatum relies on a deceit pollination system using aromatic compounds to attract pollinators. Nine aromatic compounds were identified as components of the fragrance of C. punctatum inflorescences, including two compounds that are known to be Euglossine bee attractants. However, this group of bees is not native to Florida. Of the four bee species observed to visit C. punctatum flowers in the present study, carpenter bees (Xylocopa spp.) are likely to be the main pollinators. Pollination experiments demonstrated that C. puntatum is self‐compatible, but requires a pollinator and thus does not exhibit spontaneous autogamy. In addition, the rates of fruit set were significantly higher for flowers that were outcrossed (xenogamy) than for those that were self‐crossed. Thus, the species has evolved a degree of incompatibility. Examples of natural pollination and fruit set were observed during the present study (2007–2008), but the rates of reproduction were modest as a consequence of the low plant numbers and possible changes in insect densities as a result of anthropogenic influences.

FSHβ knockout mouse model: a decade ago and into the future

In 1997, more than 10 years ago now, we first reported the phenotypes of follicle stimulating hormone (FSH) beta null mice. Since then, these mice have been useful for various physiological and genetic studies in reproductive biology. More recently, extra-gonadal functions of FSH have been discovered in bone. These studies opened up exciting avenues of new research on osteoporosis in postmenopausal women. Several genomics and proteomics tools and novel strategies to spatio-temporally restricting gene expression in vivo are available now. It is hoped that with the aid of these and other emerging technologies, an integrated network of FSH signaling pathways in various tissues would emerge in the near future. Undoubtedly, the coming 10 years should be more exciting to explore this "fertile" area of reproductive physiology research.

Population structure, flowering and seed production in the endangered Whibley wattle, Acacia whibleyana (Leguminosae: Mimosoideae).

Acacia whibleyana (Whibley wattle) is a nationally endangered wattle, endemic to the near-coastal region around Tumby Bay on the Eyre Peninsula in South Australia. Two distinct sub-populations, referred to as the Quarry and the Salt-lake populations, each contained plants growing on roadsides and in scrub fragments. Marked differences were observed in the population size structure between the two populations. The absence of juveniles on roadsides in both populations signaled potential limitations to natural recruitment. Studies of reproductive biology of scrub plants over two years (1996-1997) indicated that between 1.1% (Salt-lake) and 6.9% (Quarry) of A. whibleyana inflorescences produced fruit. Each infructescence produced an average of 1.2-1.8 pods, although up to 10 pods per infructescence were observed at the Quarry scrub in 1996. Each pod contained 4-6 seed on average, with a viability of 85%. Plants at the Salt-lake scrub generally set less fruit, produced fewer pods per infructescence, and had lower seed numbers per pod when compared with Quarry plants, differences attributable to the superior vigor of Quarry plants. A. whibleyana seeds were dispersed by ants attracted by the lipid-rich aril. The soil seed bank had a patchy distribution across both sites possibly due to seed concen- trating in the vicinity of ant nests. We concluded that the reproductive attributes studied were unlikely to constrain natural recruitment of A. whibleyana as both populations were capable of producing viable seed over the two years of this study.

The Short-Tailed Fruit Bat Carollia perspicillata: A Model for Studies in Reproduction and Development

INTRODUCTIONCarollia perspicillata has proven to be a valuable laboratory model for studies in reproduction and development. We present here an overview of the care and handling of Carollia in captivity and discuss some pertinent studies in reproductive biology. Finally, we describe various features of the genome and some of the genetic manipulations that are now possible.

Gonadal Sex Differentiation in Cultured Juvenile Flounder, Paralichthys orbignyanus (Valenciennes, 1839)

Gonadal Sex Differentiation in Cultured Juvenile Flounder, <i>Paralichthys orbignyanus</i> (Valenciennes, 1839)

Reproductive Biology and Histological Studies in Abu Mullet, Liza abu in the Water of the Khozestan Province

Reproductive Biology and Histological Studies in Abu Mullet, Liza abu in the Water of the Khozestan Province

Genetical systems biology in livestock: application to gonadotrophin releasing hormone and reproduction

Genetical systems biology or systems genetics treats the genome as the central reference point for all omics variations and is an emerging new branch of systems biology. Quantitative genetic principles were developed for high-throughput genomic, transcriptomic and metabolomic data observed in large populations. New statistical genetic models were developed for expression quantitative trait loci (eQTL), namely, marker regression eQTL mapping and marker-expression co-factor mapping. Evaluations of power to detect eQTL showed that sample size requirements are higher for detecting trans-acting genes than cis-acting genes. Power is higher for eQTL with high heritability than for eQTL with low heritability. These results will be valuable for systems genetic investigations. Gonadotrophin releasing hormone (GnRH) and its receptor gene (GnRH-R) are crucial for mammalian reproduction. Whole genome scan of eQTLs for GnRH-R gene expression in mouse showed three possible trans-eQTL regions on chr 13 and 19, harbouring regulatory genes. Applications of genetical genomics in systems biology were identified as: (1) detection and validation of causal gene for complex traits; (2) development of genetic interaction networks; (3) prediction of transcription factor binding sites and (4) in data-driven systems biology. These applications were illustrated using data on eQTL, protein network and signalling pathways for GnRH. Gpr54 (G protein-coupled receptor kinase 54), Prl (prolactin), Ins1 (insulin) and Fos (viral oncogenes) were found to be major regulators of GnRH and GnRH-R; thus validating their important role in reproduction, mammary gland development and sexual (im)maturity. These results will be useful for further study of mammalian reproductive biology.