BOC, brother of CDO, is a dorsoventral axon-guidance molecule in the embryonic vertebrate brain

The early axon scaffolding in the embryonic vertebrate brain consists of a series of ventrally projecting axon tracts that grow into a single major longitudinal pathway connected across the midline by commissures. We have investigated the role of Brother of CDO (BOC), an immunoglobulin (Ig) superfamily member distantly related to the Roundabout (Robo) family of axon-guidance receptors, in the development of this embryonic template of axon tracts in the zebrafish brain. A zebrafish homologue of BOC was isolated and shown to be expressed predominantly in the developing neural plate and later in the neural tube and developing brain. Zebrafish boc was initially highly localized to discrete bands in the mid- and hindbrain, but, as the major brain subdivisions emerged, it became more evenly expressed along the rostrocaudal axis, particularly in dorsal regions. The function of zebrafish boc was examined by a loss-of-function approach. Analysis of embryos injected with antisense morpholinos designed against boc revealed highly selective defects in the development of dorsoventrally projecting axon tracts. Loss of boc caused ventrally projecting axons, particularly those arising from the presumptive telencephalon, to follow aberrant trajectories. These data indicate that boc is an axon-guidance molecule playing a fundamental role in pathfinding during the early patterning of the axon scaffold in the embryonic vertebrate brain. (c) 2005 Wiley-Liss, Inc.

Differential expression of estrogen receptor alpha in the embryonic adrenal-kidney-gonadal complex of the oviparous lizard, Calotes versicolor (Daud.)

Estrogen signalling is critical for ovarian differentiation in reptiles with temperature-dependent sex determination (TSD). To elucidate the involvement of estrogen in this process, adrenal-kidney-gonadal (AKG) expression of estrogen receptor (ER alpha) was studied at female-producing temperature (FPT) in the developing embryos of the lizard, Calotes versicolor which exhibits a distinct pattern of TSD. The eggs of this lizard were incubated at 31.5 +/- 0.5 degrees C (100% FPT). The torso of embryos containing adrenal-kidney-gonadal complex (AKG) was collected during different stages of development and subjected to Western blotting and immunohistochemistry analysis. The ER alpha, antibody recognized two protein bands with apparent molecular weight similar to 55 and similar to 45 kDa in the total protein extracts of embryonic AKG complex of C. versicolor. The observed results suggest the occurrence of isoforms of ER alpha. The differential expression of two different protein isoforms may reveal their distinct role in cell proliferation during gonadal differentiation. This is the first report to reveal two isoforms of the ER alpha in a reptile during development. Immunohistochemical studies reveal a weak, but specific, cytoplasmic ER alpha immunostaining exclusively in the AKG during late thermo-sensitive period suggesting the responsiveness of AKG to estrogens before gonadal differentiation at FPT. Further, cytoplasmic as well as nuclear expression of ER alpha in the medulla and in oogonia of the cortex (faint activity) at gonadal differentiation stage suggests that the onset of gonadal estrogen activity coincides with sexual differentiation of gonad. Intensity and pattern of the immunoreactions of ER alpha in the medullary region at FPT suggest endogenous production of estrogen which may act in a paracrine fashion to induce neighboring cells into ovarian differentiation pathway. (C) 2014 Elsevier Inc. All rights reserved.

Contribución al estudio biológico de Loligo brasiliensis Bl

A total of 592 individuals of Loligo brasiliensis from the Mar del Plata coastal fishing area (Buenos Aires prov., Argentina) have been studied during the 1961-1964 period. From a morphological point of view the population appears to be uniform and homogeneus. A brief description of this species is given in this paper since references in the literature are scarce from the time at which Blainville (1923) first described it. The only further references are found in D'Orbigny (1835), and Ferrusac (1839), and in Hoyle (1886), and Tyron Pilsbry (1879). In this paper the species was mentioned only as a bibliographical reference on morphological or biological conditions has been found in the literature. The distribution of this species ranges from Cuba, Brazil, Uruguay to the Argentine coast, probably down to the Gulf of San Jorge. The samples had been studied with respect to various body measurements by classifing the individuals in total length classes, since body length was considered the most significant measurement. The condition factor K has been calculated for different sexes and ages, for the various length classes. The results lead to the conclusion that the smaller the length the higher is the value obtained for K and viceversa. This is due to the fact that the length of the tentacle increases considerably with increasing size. Since the tentacle are quite light the factor K diminishes accordingly. The condition factor increases considerably from December to April with an average of 0.42, decrease and becomes stable from March to October, with an average of 0.30. This is a consequence of the ripening of the sex glands. The sex-ratios are as following: year 1961, 42 % female, 42 % male; year 1962, 51 % female, 45 % male; year 1963, 46 % female, 53 % male; year 1964, 26 % female, 42 % male, 32 % indif. The great percentage of 72 undifferentiated young individuals in the 1964 (March) sampling increases the ratio of undifferentiation. A short morphological description of both ovules and spermatozoos is given. An examination of the sex glands leads to the following conclusions: a) male and female sex gland in a preparatory stage during the whole year; b) the highest percentage of ripe glands is found through, November-March; e) the spawning appears to precede rather slowly, but this certain since the spawning environment does not coincide with the natural habitat of the species. Few spawning individuals were found; d) sexual differentiation begins at body lenght from 30 to 40 mm; i.e. a total length of approximately 145 mm. At a body length of 70 mm. the hectocotilication (sexual character) begins to appear. In June 1962, a sample gathered at Rawson (Chubut) was analyzed. The conclusion was reached that the sex glands in this population are in an earlier stage of development in comparison with those from the Mar del Plata area. Also the average for the factor K which were found to be 0.17 for females and 0.19 for male, are rather low for that date. These physiological facts are possibly related to morphological differences which will be pointed out in a forthcoming publication. Some very typical associations with Artemesia longinaris and Percophis brasiliensis were found. Cannibalism has been observed.

Le rôle de l'hormone anti-müillerienne dans la régulation du fonctionnement de l'ovaire. Revue de la littérature

Anti-mullerian hormone, also called AMH, belongs to the large family of transforming growth factor P. Its role in the sexual differentiation of male fetus is now well known. Recently, AMH has been demonstrated to play an important role in the ovarian function. In fact, AMH seems to regulate the kinetics of follicular development, inhibiting the follicular recruitment and the follicular growth. Thus, this intra-gonadic cybernin could be a decisive determinant of the rapidity of follicular pool exhaustion. Today, some experimental data from the literature suggest that AMH could be a reliable marker of ovarian reserve. This review summarizes the present knowledge about AMH and its role in physiology but also in ovarian pathology.

Genetic disorders and spermatogenesis.

Male infertility affects one man in twenty and a genetic basis seems likely in at least 30% of those men. Genetic regulation of fertility involves the inter-related processes of testicular development, spermatogenesis (involving germ cell mitosis, meiosis and spermatid maturation), and their endocrine and paracrine regulation. In regard to spermatogenesis, particular attention has been given to the Yq11 region, where some spermatogenesis genes ('azoospermia factors') appear to be located. Several candidate genes have been identified but have not been shown to have a defined or essential role in spermatogenesis. Microdeletions of Yq11 are found in approximately 15% of azoospermic or severely oligospermic men. The complexity of the genetic control of male fertility is demonstrated by the evidence for genes involved in spermatogenesis and sexual differentiation on the X chromosome and autosomes. Better understanding of the genetic regulation of normal spermatogenesis will provide new probes for clinical studies; however, at present the majority of spermatogenic failure remains without an identified genetic linkage. The advent of intracytoplasmic sperm injection permits fertility in many previously sterile men and presents the possibility of their transmission of infertility; appropriate counselling is required.

Atresia anal, fístula uretrorretal congênita, bolsa escrotal acessória e pseudo-hermafroditismo em bezerro mestiço

Neste trabalho, é descrito o caso de um bezerro mestiço recém-nascido que apresentava atresia anal tipo 2, fístula uretrorretal congênita, bolsa escrotal bífida e pseudo-hermafroditismo masculino. O principal sinal clínico era a eliminação de fezes por meio do óstio prepucial, uma apresentação incomum em casos de fístula uretrorretal em animais machos. Apesar de o quadro de atresia anal ser relativamente comum nessa espécie, os outros defeitos congênitos encontrados são pouco frequentes.

Escolha de parceiros na adolescência

Mate choice is a component of sexual selection. Trying to understand the patterns of this process, several studies have emphasized the adaptive value of sexual differences and their influence on the assessment of the market value. The pattern for adults presented on the scientific literature, which is based on the preference for certain characteristics, shows that men search a partner who shows high value of fecundity and fertility, thus looking for partners with the ability of being pregnant and nursing their offspring. On the other hand, women look for partners with high socioeconomic status, which is strongly associated with the ability to protect and provide resources for them and their offspring. Surprisingly, there is few works that investigated the mate choice patterns during the beginning of the period of sexual differentiation on the morphological, physiological and behavioral traits. The aim of this study was to investigate mate choice patterns in adolescence in order to describe their preferences and contribute to the understanding of human reproductive behavior. Took part of this research 1,232 students from educational institutions of Natal, Brazil, and visitors to the Scientific, Technological and Cultural Fair UFRN. In the Experimental Study 1, we applied a questionnaire to evaluate the importance of certain characteristics, assessed the degree of romantic involvement and real and ideal partners age preference. In the Experimental Study 2, we did a survey of characteristics considered relevant and evaluate the importance of these characteristics in mate choice. The Experimental Study 3 brought an investigation of mate choice patterns based on self-assessment of adolescents, evaluating ideal partner for a short-term and long-term relationships and actual partner. We found that adolescents are motivated to live romantic experiences. We also observed a preference for partners of similar age to that described for adults. Finally, we found similarities and differences in the preferences for characteristics in real and ideal partners in relation to the adult pattern. In addition, we observed high similarity on the self-assessment and assessment of real and ideal partners. We suggest that in the mate choice, adolescents are similar to young adults in some aspects but not all. Our results show the relevance of the reproductive behavior investigation in this human developmental period and reinforce that further studies should contribute to the understanding of human behavior in terms of ontogenetic development and their evolutionary history.

Neuroendocrine and reproductive aspects of adult male rats exposed neonatally to an antiestrogen

The present study was designed to investigate the effects of a single dose of an estrogen antagonist-clomiphene-during neonatal life, on later neuroendocrine system and reproductive performance. Immediately after birth, male pups received clomiphene citrate (s.c.). At adulthood, although testosterone levels and wet weights of reproductive organs were not altered, the treatment induced an increased number of spermatozoa and a delay in the transit time in the cauda epididymis. Additionally, there was impairment of sexual behavior evidenced by a delay in the latencies to the first mount and first intromission. Treated rats also showed decreased dopaminergic and serotonergic neurotransmissions in the hypothalamus and decreased dopaminergic neurotransmission in the striatum. The decreased dopaminergic activity could be related to the lower sexual motivation observed. These results indicate the necessity of preventing exposure to drugs that may impair sexual differentiation, which can compromise later mating success as well as the capacity to generate descendants. (c) 2006 Elsevier B.V. All rights reserved.

Copulatory efficiency and fertility in male rats exposed perinatally to flutamide

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

Early juvenile development of Armases rubripes (Rathbun 1897) (Crustacea, Brachyura, Sesarmidae) and comments on the morphology of the megalopa and first crab

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

Juvenile development and growth patterns in the mud crab Eurytium limosum (Say, 1818) (Decapoda, Brachyura, Xanthidae) under laboratory conditions

The post-larval development of the mud crab Eurytium limosum was studied under laboratory conditions by using the offspring of ovigerous females collected at the Comprido River mangrove, SP, Brazil. The first crab stage is fully described and the juvenile development, until crab stage 10, is examined with emphasis on morphological change, sexual differentiation and growth patterns. The carapace of the first crab stage is nearly square as observed in other xanthids, becoming similar to adults only at stage 15. The sexes can be distinguished from stage four, based on the number of pleopods and their morphology. While the intermoult period increases, the moult percentage decreases at each stage. The abdominal allometric growth is sex-dependent, with males showing a negative (b=0.71) and females an isometric (b=0.95) relative growth pattern. Male gonopods undergo a positive allometric growth, and their shape changes remarkably until sexual maturity. The cheliped dentition can be observed after stage 4. Regardless of sex, most crabs have a molariform right cheliped, which is thought to aid the handling of asymmetric prey such as gastropods.

Mitosis and cell death in the optic lobes of workers, queens and drones of the honey bee (Apis mellifera) during metamorphosis

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

Perinatal estrogen exposure: Later repercussion on the fertility of rats

The aim of the present study was to investigate the effects of perinatal estrogen exposure in the fertility of rats. Thus, rats were treated with estrogen on the 21st or 22nd day of intra-uterine life or treated with estrogen immediately after birth. It was observed that the testicular descent of males and beginning of puberty of females were advanced in all estrogen-treated groups. The females from estrogen-treated groups showed reduced frequency of estrous in 15 consecutive days of study, and there was an increase in estrous duration. Their fertility also were impaired and a reduction in the number of alive fetuses, as well as enhancement of pre- and postimplantation loss, mainly in the group treated with estrogen on the 21st day of intra-uterine life. However, the alterations observed in the fertility of estrogen-treated male rats were slighter and only females mated with male rats from the group treated with estrogen immediately after birth showed enhanced preimplantation loss. We suggest that the reproductive function is impaired by exposure to estrogen in the perinatal life of rats, and that the mechanisms involved in this effect are distinct for males and females. (C) 1997 Elsevier B.V.

Prenatal testosterone supplementation alters puberty onset, aggressive behavior, and partner preference in adult male rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Gene expression in placentation of farm animals: An overview of gene function during development

Eutherian mammals share a common ancestor that evolved into two main placental types, i.e., hemotrophic (e.g., human and mouse) and histiotrophic (e.g., farm animals), which differ in invasiveness. Pregnancies initiated with assisted reproductive techniques (ART) in farm animals are at increased risk of failure; these losses were associated with placental defects, perhaps due to altered gene expression. Developmentally regulated genes in the placenta seem highly phylogenetically conserved, whereas those expressed later in pregnancy are more species-specific. To elucidate differences between hemotrophic and epitheliochorial placentae, gene expression data were compiled from microarray studies of bovine placental tissues at various stages of pregnancy. Moreover, an in silico subtractive library was constructed based on homology of bovine genes to the database of zebrafish - a nonplacental vertebrate. In addition, the list of placental preferentially expressed genes for the human and mouse were collected using bioinformatics tools (Tissue-specific Gene Expression and Regulation [TiGER] - for humans, and tissue-specific genes database (TiSGeD) - for mice and humans). Humans, mice, and cattle shared 93 genes expressed in their placentae. Most of these were related to immune function (based on analysis of gene ontology). Cattle and women shared expression of 23 genes, mostly related to hormonal activity, whereas mice and women shared 16 genes (primarily sexual differentiation and glycoprotein biology). Because the number of genes expressed by the placentae of both cattle and mice were similar (based on cluster analysis), we concluded that both cattle and mice were suitable models to study the biology of the human placenta. (C) 2011 Elsevier B.V. All rights reserved.