Histone H2A Has a Novel Variant in Fish Oocytes

Histone variants and their modification have significant roles in many cellular processes. In this study, we identified and characterized the histone H2A variant h2af1o in fish and revealed its oocyte-specific expression pattern during oogenesis and embryogenesis. Moreover, posttranslational modification of H2af1o was observed that results from phosphorylation during oocyte maturation. To understand the binding dynamics of the novel core histone variant H2af1o in nucleosomes, we cloned ubiquitous gibel carp h2afx as a conventional histone control and investigated the dynamic exchange difference in chromatin by fluorescence recovery after photobleaching. H2af1o has significantly higher mobility in nucleosomes than ubiquitous H2afx. Compared with ubiquitous H2afx, H2af1o has a tightly binding C-terminal and a weakly binding N-terminal. These data indicate that fish oocytes have a novel H2A variant that destabilizes nucleosomes by protruding its N-terminal tail and stabilizes core particles by contracting its C-terminal tail. Our findings suggest that H2af1o may have intrinsic ability to modify chromatin properties during fish oogenesis, oocyte maturation, and early cleavage.

Female reproductive biology of two sympatric incirrate octopod species, Adelieledone polymorpha (Robson 1930) and Pareledone turqueti (Joubin 1905) (Cephalopoda : Octopodidae), from South Georgia

The reproductive biology of two species of endemic Southern Ocean octopods was investigated around the sub-Antarctic islands of South Georgia and Shag Rocks. The females of both the species produce few, large eggs. This appears to be governed by phylogenetic constraint. No evidence was found for ontogenetic migration or seasonality associated with gonad maturation. Based on oocyte length frequency distributions and observations of oocyte development within the ovary, it is possible that both species could have either a single or multiple-batch spawning strategy. Pareledone turqueti ovaries contained fewer larger oocytes than those of Adefieledone polymorpha, which may help to reduce competition for resources immediately after hatching.

AINT/ERIC/TACC: an expanding family of proteins with C-terminal coiled coil domains:an expanding family of proteins with C-terminal coiled coil domains

The AINT/ERIC/TACC genes encode novel proteins with a coiled coil domain at their C-terminus. The founding member of this expanding family of genes, transforming acidic coiled coil 1 (TACC1), was isolated from a BAC contig spanning the breast cancer amplicon-1 on 8p11. Transfection of cells in vitro with TACC1 resulted in anchorage-independent growth consistent with a more "neoplastic" phenotype. Database searches employing the human TACC1 sequence revealed other novel genes, TACC2 and TACC3, with substantial sequence homology particularly in the C-terminal regions encoding the coiled coil domains. TACC2, located at 10q26, is similar to anti-zuai-1 (AZU-1), a candidate breast tumour suppressor gene, and ECTACC, an endothelial cell TACC which is upregulated by erythropoietin (Epo). The murine homologue of TACC3, murine erythropoietin-induced cDNA (mERIC-1) was also found to be upregulated by Epo in the Friend virus anaemia (FVA) model by differential display-PCR. Human ERIC-1, located at 4p16.3, has been cloned and encodes an 838-amino acid protein whose N- and C-terminal regions are highly homologous to the shorter 558-amino acid murine protein, mERIC-1. In contrast, the central portions of these proteins differ markedly. The murine protein contains four 24 amino acid imperfect repeats. ARNT interacting protein (AINT), a protein expressed during embryonic development in the mouse, binds through its coiled coil region to the aryl hydrocarbon nuclear translocator protein (ARNT) and has a central portion that contains seven of the 24 amino acid repeats found in mERIC-1. Thus mERIC-1 and AINT appear to be developmentally regulated alternative transcripts of the gene. Most members of the TACC family discovered so far contain a novel nine amino acid putative phosphorylation site with the pattern [R/K]-X(3)-[E]-X(3)-Y. Genes with sequence homology to the AINT/ERIC/TACC family in other species include maskin in Xenopus, D-TACC in Drosophila and TACC4 in the rabbit. Maskin contains a peptide sequence conserved among eIF-4E binding proteins that is involved in oocyte development. D-TACC cooperates with another conserved microtubule-associated protein Msps to stabilise spindle poles during cell division. The diversity of function already attributed to this protein family, including both transforming and tumour suppressor properties, should ensure that a new and interesting narrative is about to unfold.

Embryo Mitochondrial DNA Depletion Is Reversed During Early Embryogenesis in Cattle

The extensive replication of mitochondria during oogenesis and the wide variability in mitochondrial DNA ( mtDNA) copy numbers present in fully grown oocytes indicate that mtDNA amount may play an important role during early embryogenesis. Using bovine oocytes derived from follicles of different sizes to study the influence of mtDNA content on development, we showed that oocytes obtained from small follicles, known to be less competent in developing into blastocysts, contain less mtDNA than those originating from larger follicles. However, because of the high variability in copy number, a more accurate approach was examined in which parthenogenetic one-cell embryos were biopsied to measure their mtDNA content and then cultured to assess development capacity. Contrasting with previous findings, mtDNA copy number in biopsies was not different between competent and incompetent embryos, indicating that mtDNA content is not related to early developmental competence. To further examine the importance of mtDNA on development, one-cell embryos were partially depleted of their mtDNA (64% +/- 4.1% less) by centrifugation followed by the removal of the mitochondrial-enriched cytoplasmic fraction. Surprisingly, depleted embryos developed normally into blastocysts, which contained mtDNA copy numbers similar to nonmanipulated controls. Development in depleted embryos was accompanied by an increase in the expression of genes (TFAM and NRF1) controlling mtDNA replication and transcription, indicating an intrinsic ability to restore the content of mtDNA at the blastocyst stage. Therefore, we concluded that competent bovine embryos are able to regulate their mtDNA content at the blastocyst stage regardless of the copy numbers accumulated during oogenesis.

Diversidade Ictiofaunística e Ecologia reprodutiva de uma espécie nativa de peixe da Bacia Piranhas-Assu, RN

The Caatinga biome is rich in endemic fish species fauna. The present study the results of fish faunal surveys conducted in the hydrographic basin of Piranhas-Assu of the Brazilian Caatinga biome. The fish samples collected were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families (Characidae, Curimatidae, Auchenipteridae, Anostomidae, Prochilodontidae, Erythrinidae, Cichlidae, Sciaenidae, Heptapteridae, Loricariidae, Synbranchidae) and 22 species, of which 17 are endemic and five have been introduced from other basins. The order Characiformes was the most representative in number of species (46,35% ) followed by Perciformes (35,38%), Siluriformes (17,44%) and Synbranchiformes (0,5%). The Nile tilapia, Oreochomis niloticus, the only exotic species, was most expressive in number of individuals (24.92%) followed by the native species piau preto, Leporinus piau (18,77 %). Considering the relative frequency of occurrence of the 22 species, 13 were constant, five were accessory and four were occasional. This study investigated the reproductive ecology of an endemic fish black piau, Leporinus piau from the Marechal Dutra reservoir, Acari, Rio Grande do Norte. Samplings were done on a monthly basis from January to December 2009, and a total of 211 specimens were captured. The environmental parameters such as rainfall, temperature, pH, electrical conductivity and dissolved oxygen of water were recorded. The sampled population showed a slight predominance of males (55%), however females were larger and heavier. Both sexes of L. piau showed positive allometric growth, indicating a higher increase of weight than length. The first sexual maturation of males occurred at smaller size, with 16.5 cm in total length than females (20.5 cm). During the reproductive period, the condition factor and gonadosomatic index (GSI) of L. piau were negatively correlated. This species has large oocytes with a high mean fecundity of 54.966 with synchronous oocyte development and total spawning

Dinâmica reprodutiva e parasitária de quatro espécies de peixes das águas costeiras do Sudoeste do Oceano Atlântico, Brasil

The present study investigated the reproductive dynamics and parasitism of four species of marine fishes: serra Spanish mackerel, Scomberomorus brasiliensis, Atlantic leatherjacks, Oligoplites saurus and O. palometa,, and Atlantic bumper, C. chrysurus, during the period of August, 2005 to July, 2007, in the coastal waters of Southwest Atlantic Ocean, Brazil. The collected fish samples were measured, weighed, dissected, the gonads were weighed and examined to separate the sex. The gonadosomatic index (GSI), fecundity, type of spawning, the breeding season, the macro and microscopic characterization of the gonads were determined. The ectoparasites from the branchial chambers and bucal cavity of the fish were collected, measured, weighed and identified. The sex ratio of the study fish species were approximately 1M:1F, however, there was a predominance of males of O. palometa (3M:2F). The GSI of fishes varied according to their reproductive cycle and the stage of gonadal maturation. The highest values of GSI and the spawning period coincided with the rainy period of the region. The females presented total spawning and the fecundity was positively correlated with the weight of the ovary and the body. Four stages of development of the gonads immature, maturing, mature and spent were identified macroscopically and histological analyses of ovaries revealed the different phases of oocyte development. Three species of isopod parasites were identified in the study fishes: Livoneca redmmanni, Rocinela signata and Cimothoa spinipalpa. The first two species occurred in the branchial cavities of C. chrysurus and S. brasiliensis. The isopod C.spinipalpa (a new species) was registered for the first time in the bucal cavity of O. saurus and O. palometa. The parasitic isopods preferred the branchial chambers and the bucal cavity of the host fishes as these were protected microhabitats. The isopods parasitized the immature, maturing and mature fishes. The prevalence of infection of isopods in the hosts varied from 16 to 21%, though in O. palometa it was 60%. In the rainy period the highest isopod parasitic occurrence was registered, however, this did not prejudice the normal reproductive cycle of the host fish.

Influence of Superovulatory Protocols on In Vitro Production of Nellore (Bos indicus) Embryos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphology, ultramorphology and histology of ovaries of workers and mated queens of Pachycondyla striata ants (Hymenoptera : Ponerinae)

The aim of the present work is to perform morphological and histological studies of the ovaries of workers and mated queens of Pachycondyla striata ants, which belong to the subfamily Ponerinae. The ovaries, after being removed, were schematized. Next, historesin and electronic scanning microscopy techniques were applied, making it possible to note that the left ovary owns a greater number of ovarioles when compared to the right one (workers - 7 to the right and 8 to the left; queens - 6 to the right and 7 to the left) and that the ovarioles of workers present a rather wrinkled aspect due to the fact that they are not developed. The same situation does not occur in mated queens once they always present oocytes in distinct development phases in their ovarioles. Histologically it was observed that the ovarioles are of the meroistic polytrophic kind. Inside the ovarioles of workers, germinative cells were observed in their distal portion, but their lumen were empty. on the other hand, ovarioles of mated queens presented the germinative cells as well as oocytes in different degrees of development, although more than one developing oocyte was never observed in the interior of each ovariole. It was possible to note the presence of follicular epithelium, chorion and vitellin membrane in oocytes of mated queens, which change morphologically according the oocyte development stage.

Ultrastructure of oocytes of the Urostreptus atrobrunneus (Diplopoda, Spirostreptida, Spirostreptidae): A potential urban centers plague

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reproduction of Oligosarcus hepsetus (Cuvier, 1829) (Characiforms) in the Serra do Mar State Park, São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Correlação entre os dismorfismos oocitários e os resultados da fertilização in vitro

In assisted reproduction, the selection of gametes to achieve better clinical outcomes is a crucial task of embryologists. The quality of the oocyte is a key factor in female fertility, reflecting the intrinsic potential of gamete development, and has a vital role not only in conception but also in subsequent embryonic development. Oocyte dysmorphisms are classified into two types: cytoplasmic, including the presence of granules and/or cytoplasmic inclusions (vacuoles, refractive bodies, and aggregates of the endoplasmic reticulum), and extracytoplasmic (changes in the shape of the oocyte, the zona pellucida, the space perivitelline changes and the polar body). Variations in oocyte morphology may occur due to factors such as the age of women, genetic problems and changes in the hormonal environment to which the oocyte is exposed in ovarian hyperstimulation. The classification of oocyte morphology and its correlation with embryo development and pregnancy rates are controversial in the literature. Several studies show no association between oocyte dysmorphisms and the results of in vitro fertilization, while others report an association between oocyte morphology and embryo development. These differences in the results can be explained by the use of different morphological criteria due to a lack of standardization of oocyte evaluation. © Todos os direitos reservados a SBRA - Sociedade Brasileira de Reprodução Assistida.

Rhipicephalus sanguineus (Acari: Ixodidae) female ticks exposed to castor oil (Ricinus communis): An ultrastructural overview

Tick control has been accomplished through the use of synthetic acaricides, which has created resistant individuals, as well as contaminating the environment and nontarget organisms. Substances of plant origin, such as oils and extracts of eucalyptus and neem leaves, have been researched as an alternative to replace the synthetic acaricides. Ricinoleic acid esters from castor oil have recently been shown as a promising alternative in eliminating bacterial contamination during ethanol fermentation, by acting as an effective biocide. The same positive results have been observed when these esters are added to the food given to tick-infested rabbits. This study tested the effect of these substance on the reproductive system of Rhipicephalus sanguineus females, added to rabbit food, more specifically on oogenesis. For this, four groups were established: four control groups (CG1, CG2, CG3, and CG4) and four treatment groups (TG1, TG2, TG3, and TG4) with one rabbit in each (New Zealand White), used as hosts. After full 4 days feeding (semi-engorgement), the females were collected and had their ovaries extracted. In this study, it was observed that R. sanguineus females exposed to esters had their ovaries modified, which was demonstrated through transmission electron microscopy techniques. The addition of ricinoleic esters to the diet of tick-infested rabbits revealed how toxic such substances are for the cytoplasmic organelles of oocytes and pedicel cells. These compounds can change the morphophysiology of germ and somatic cells, consequently influencing their viability and, therefore, confirming that the ricinoleic acid esters from castor oil are a promising substance in the control of R. sanguineus. © 2012 Springer-Verlag Berlin Heidelberg.

Female germ cell renewal during the annual reproductive cycle in Ostariophysians fish

The objective was to characterize female germ cell renewal during the annual reproductive cycle in two species of ostariophysian fish with distinct reproductive strategies: a siluriform, Pimelodus maculatus, in which oocyte development is group synchronous and the annual reproductive period is short; and a characiform, Serrasalmus maculatus, with asynchronous oocyte development and a prolonged reproductive period. These reproductive strategies result in fish determinate and indeterminate fecundity, respectively. Annual reproductive phases were determined by biometric and histologic analysis of gonads and interpreted according to new proposals for phase classification and stages of oocyte development (with special attention to germinal epithelium activity). Histologically, there were two types of oogonia in the germinal epithelium: single oogonia and those in mitotic proliferation. Oogonial proliferation and their entry into meiosis resulted in formation of cell nests (clusters of cells in the ovarian lamellae). Morphometric analysis was used to estimate germ cell renewal. Based on numbers of single oogonia in the lamellar epithelium, and nests with proliferating oogonia or early prophase oocytes throughout the annual reproductive cycle, oogonial proliferation and entrance into meiosis were more intense during the regenerating phase and developing phase, but decreased sharply (P < 0.05) during the spawning-capable phase. Oogonial proliferation gradually recovered during the regressing phase. We concluded that, independent of species or features of the reproductive cycle, germ cell renewal occurred during the regenerating phase, ensuring availability of eggs for the spawning event. © 2013 Elsevier Inc.

Reproductive biology of two macrourid fish, Nezumia aequalis and Coelorinchus mediterraneus, inhabiting the NW Mediterranean continental margin (400-2000m)

Nezumia aequalis and Coelorinchus mediterraneus are abundant species on the upper and lower continental slopes, respectively, in the Mediterranean Sea. A study on the reproductive strategy of the two species was conducted on the Catalan margin (NW Mediterranean). The reproductive cycle of both species was investigated using visual analyses of gonads and histological screening. The shallower species, N. aequalis, showed continuous reproduction with a peak of spawning females in winter months. In contrast, the deeper-living species, C. mediterraneus, showed semi-continuous reproduction with a regression period during the spring. Juveniles of N. aequalis were present in all seasons, but most abundant in the spring. Only two juveniles of C. mediterraneus were found. Both species had asynchronous oocyte development. The average fecundity of N. aequalis was 10,630 oocytes per individual, lower than known for the same species in the Atlantic Ocean. The fecundity of C. mediterraneus was measured for the first time in this study, with an average of 7693 oocytes per individual. Males of both species appear to have semi-cystic spermatogenesis. © 2013 Elsevier Ltd.