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Sexual maturation

Alexei A Maklakov, Urban Friberg
Male nematodes secrete pheromones that accelerate the somatic senescence of potential mates. A new study shows that this harm most likely is an unintended by-product of the males' aim to speed up sexual maturation and delay reproductive senescence of future partners.
October 24, 2016: Current Biology: CB
Michael M Kasumovic, Zhiliang Chen, Marc R Wilkins
BACKGROUND: Ecological and evolutionary model organisms have provided extensive insight into the ecological triggers, adaptive benefits, and evolution of life-history driven developmental plasticity. Despite this, we still have a poor understanding of the underlying genetic changes that occur during shifts towards different developmental trajectories. The goal of this study is to determine whether we can identify underlying gene expression patterns that can describe the different life-history trajectories individuals follow in response to social cues of competition...
October 24, 2016: BMC Genomics
J Rojas-Ticona, M Fernández-Ibieta, L Nortes Cano, O Girón-Vallejo, P Reyes Ríos, I Martínez Castaño, V Villamil, J I Ruiz Jiménez
OBJECTIVES: To describe our experience in testicular and paratesticular tumors during the prepubertal stage, focusing especially on its character of benignity/malignancy and surgical treatment used. MATERIAL AND METHODS: Retrospective review of all testicular tumors in children under 12 years diagnosed and treated in our clinical setting from 1998-2015. Data on their presentation, study and management were collected. RESULTS: 17 children with prepubertal testicular tumors were identified...
January 15, 2016: Cirugía Pediátrica: Organo Oficial de la Sociedad Española de Cirugía Pediátrica
Collins C Iwuji, Nuala McGrath, Tulio de Oliveira, Kholoud Porter, Deenan Pillay, Martin Fisher, Melanie Newport, Marie-Louise Newell
INTRODUCTION: Remarkable strides have been made in controlling the HIV epidemic, although not enough to achieve epidemic control. More recently, interest in biomedical HIV control approaches has increased, but substantial challenges with the HIV cascade of care hinder successful implementation. We summarise all available HIV prevention methods and make recommendations on how to address current challenges. DISCUSSION: In the early days of the epidemic, behavioural approaches to control the HIV dominated, and the few available evidence-based interventions demonstrated to reduce HIV transmission were applied independently from one another...
November 30, 2015: Journal of AIDS & Clinical Research
Jeffrey L Langston, Todd M Myers
The present experiments determined the intramuscular LD50 of VX in male Göttingen minipigs at two stages of development. In pubertal animals (115days old), the LD50 of VX was indeterminate, but approximated 33.3μg/kg. However, in sexually mature animals (152days old), the LD50 was estimated to be only 17.4μg/kg. Signs of nerve agent toxicity in the Göttingen minipig were similar to those described for other species, with some notable exceptions (such as urticaria and ejaculation). Latencies to the onset of sustained convulsions were inversely related to the administered dose of VX in both ages of minipigs...
October 20, 2016: Toxicology Letters
M P Machado, I Matos, A R Grosso, M Schartl, M M Coelho
Sex determination is a highly variable process that utilizes many different mechanisms to initiate the cascade of differentiation processes. The molecular pathways controlling sexual development are less conserved than previously assumed, and appear to require active maintenance in some species; indeed, the developmental decision of gonad phenotype in gonochoristic species is not fixed at an early developmental stage. Much of the knowledge about sex determination mechanisms was derived from research on gonochoristic, non-seasonal breeders...
October 22, 2016: Molecular Reproduction and Development
Akihisa Kangawa, Masayoshi Otake, Satoko Enya, Toshinori Yoshida, Masatoshi Shibata
Microminipigs are becoming increasingly attractive alternatives for various experimental applications, such as general toxicology studies, owing to their manageable size. However, there are limited studies on the male reproductive organs of microminipigs, particularly on the histological aspects of sexual maturity. To clarify the development of male reproductive organs, 35 male microminipigs, aged 0 to 12 months, were used in this study. Histological and histomorphological evaluation was performed based on spermatogenic development, measurement of tubular structure in testes and epididymides, and histological progress of accessory glands...
October 21, 2016: Toxicologic Pathology
Jilun Hou, Guixing Wang, Xiaoyan Zhang, Yufen Wang, Zhaohui Sun, Fei Si, Xiufeng Jiang, Haijin Liu
Clonal fishes are useful tools in biology and aquaculture studies due to their isogenicity. In Japanese flounder (Paralichthys olivaceus), a group of homozygous clones was created by inducing meiogynogenesis in eggs from a mitogynogenetic homozygous diploid. As the clones reached sexual maturity, meiogynogenesis was again induced in order to produce a 2(nd) generation clonal group of Japanese flounder. After 3 months, there were 611 healthy, surviving individuals. Twenty-four microsatellite markers, that covered all the linkage groups of Japanese flounder, were used to identify the homozygosity of the 2(nd) generation clones; no heterozygous locus was detected...
October 21, 2016: Scientific Reports
M E F Oliveira, H Ayres, L G Oliveira, E Oba, R T Kridli, P M Bartlewski, J F Fonseca, S D Bicudo, W R R Vicente
This study was conducted to document the pattern of antral follicular wave emergence throughout the 14-day, progesterone (P4)-based estrous synchronization protocol in ewes that were maintained in subtropical conditions, during the period of increasing day lengths (ID), decreasing day lengths (DD), and the transitional period (TP). In addition, the influence of ovarian status (i.e., size of ovarian antral follicles and the presence of corpora lutea) at the outset of P4 treatment on ensuing ovarian follicular wave development was examined...
September 9, 2016: Animal Reproduction Science
Maria Carla de Francesco, Anna Loy
Feeding adaptation, social behaviour, and interspecific interactions related to sexual dimorphism and allometric growth are particularly challenging to be investigated in the high sexual monomorphic Delphinidae. We used geometric morphometrics to extensively explore sexual dimorphism and ontogenetic allometry of different projections of the skull and the mandible of the bottlenose dolphin Tursiops truncatus. Two-dimensional landmarks were recorded on the dorsal, ventral, lateral, and occipital views of the skull, and on the lateral view of the left and the right mandible of 104 specimens from the Mediterranean and the North Seas, differing environmental condition and degree of interspecific associations...
2016: PloS One
Denys deCatanzaro, Tyler J Pollock
Estradiol-17β (E2) plays critical roles in female maturation, sexual receptivity, ovulation, and fertility. In many mammals, contact with males can similarly affect these female parameters, while male excretions contain significant quantities of E2 We administered radiolabeled estradiol ([(3)H]E2) to male mice in doses representing a small fraction of their endogenous E2 These males were paired with sexually-receptive females, and radioactivity was traced into the females' systems. In Experiment 1, males were given [(3)H]E2 at 24 and 1 h prior to mating...
October 6, 2016: Journal of Endocrinology
Ramona Jühlen, Dana Landgraf, Angela Huebner, Katrin Koehler
It has been shown that the nucleoporin ALADIN plays a significant role in the redox homeostasis of the cell but its function in steroidogenesis contributing to adrenal atrophy in triple A syndrome remains largely unknown. In an attempt to identify new interaction partners of ALADIN, co-immunoprecipitation followed by proteome analysis was conducted in different expression models using the human adrenocortical tumour cell line NCI-H295R. Our results suggest an interaction of ALADIN with the microsomal protein PGRMC2...
October 17, 2016: Biology Open
Justin D Vidal
Evaluation of the female reproductive system in a general toxicity setting can be challenging for the toxicologic pathologist due to the cyclic nature of the estrous and menstrual cycles, timing of puberty and reproductive senescence, and species differences. Age in particular can have a significant impact on the histologic appearance of the female reproductive system and create challenges when trying to distinguish test article-related findings from normal developmental or senescent changes. This review describes the key physiologic and histologic features of immaturity, the transition through puberty, sexual maturity, and reproductive senescence in the female reproductive system, with an emphasis on practical applications for the toxicologic pathologist, and includes recommendations for distinguishing and documenting these developmental periods...
October 17, 2016: Toxicologic Pathology
Virginia Mela, Sara Jimenez, Alejandra Freire-Regatillo, Vicente Barrios, Eva-María Marco, Ana-Belén Lopez-Rodriguez, Jesús Argente, María-Paz Viveros, Julie A Chowen
The neonatal leptin surge, occurring from postnatal day (PND) 5 to 13 and peaking at PND9 in rodents, is important for the development of neuroendocrine circuits involved in metabolic control and reproductive function. We previously demonstrated that treatment with a leptin antagonist from PND 5 to 9, coincident with peak leptin levels in the neonatal surge, modified trophic factors and markers of cell turnover and neuronal maturation in the hypothalamus of peri-pubertal rats. The kisspeptin system and metabolic neuropeptide and hormone levels were also modified...
October 14, 2016: Peptides
Leigh A M Demain, Gerard S Conway, William G Newman
Increasingly, mitochondria are being recognised as having an important role in fertility. Indeed in assisted reproductive technologies mitochondrial function is a key indicator of sperm and oocyte quality. Here, we review the literature regarding mitochondrial genetics and infertility. In many multisystem disorders caused by mitochondrial dysfunction death occurs prior to sexual maturity, or the clinical features are so severe that infertility may be under-reported. Interestingly, many of the genes linked to mitochondrial dysfunction and infertility have roles in the maintenance of mitochondrial DNA or in mitochondrial translation...
October 17, 2016: Clinical Genetics
Neha Chaturvedi, Praveen K Bharti, Archana Tiwari, Neeru Singh
Transmission blocking malaria vaccines are aimed to block the development and maturity of sexual stages of parasite within mosquitoes. The vaccine candidate antigens (Pfs25, Pfs48/45, Pfs230) that have shown transmission blocking immunity in model systems are in different stages of development. These antigens are immunogenic with limited genetic diversity. Pfs25 is a leading candidate and currently in phase I clinical trial. Efforts are now focused on the cost-effective production of potent antigens using safe adjuvants and optimization of vaccine delivery system that are capable of inducing strong immune responses...
June 2016: Indian Journal of Medical Research
Charlene Steinhausen, Lyuba Zehl, Michaela Haas-Rioth, Kerstin Morcinek, Wolfgang Walkowiak, Stefan Huggenberger
The general assumption that brain size differences are an adequate proxy for subtler differences in brain organization turned neurobiologists toward the question why some groups of mammals such as primates, elephants, and whales have such remarkably large brains. In this meta-analysis, an extensive sample of eutherian mammals (115 species distributed in 14 orders) provided data about several different biological traits and measures of brain size such as absolute brain mass (AB), relative brain mass (RB; quotient from AB and body mass), and encephalization quotient (EQ)...
2016: Frontiers in Neuroanatomy
S K Stell, P Moller
This osteological survey of 249 specimens of Brevimyrus niger ranging in size from 44 to 137 mm standard length (LS ) demonstrated that developmental changes in anal-fin morphology can serve as a predictor of sexual maturity in this species. Anal-fin ray bases begin to expand when fish reach c. 90 mm LS at which size and above there were roughly equal numbers of individuals observed with expanded and unmodified anal-fin bases, reflecting a 1:1 sex ratio.
October 14, 2016: Journal of Fish Biology
Min Wu, Qingxiong Yu, Qingfeng Li
Alopecia is a dermatological condition with limited therapeutic options. Only two drugs, finasteride and minoxidil, are approved by FDA for alopecia treatment. However, little is known about the differences in adverse effects between these two drugs. We examined the clinical reports submitted to the FDA Adverse Event Reporting System (FAERS) from 2004 to 2014. For both female and males, finasteride was found to be more associated with reproductive toxicity as compared to minoxidil. Among male alopecia cases, finasteride was significantly more concurrent with several forms of sexual dysfunction...
October 12, 2016: Oncotarget
Karen Vignale, Justina V Caldas, Judy A England, Nirun Boonsinchai, Phiphob Sodsee, Monticha Putsakum, Erik D Pollock, Sami Dridi, Craig N Coon
A study was conducted to evaluate the effect of four different feeding regimens on breast muscle protein turnover in broiler breeder Cobb-500 parent stock (PS) pullets and breeder hens. The four feeding regimens based on BW curves utilized for the study were as follows: Everyday feeding (STD-ED) (Cobb Standard BW curve), skip-a-day feeding (STD-SKIP) (Cobb Standard BW curve), lighter BW (LBW-SKIP) (BW curve 20% under), and heavier BW (HBW-SKIP) (BW curve 20% over). Each feeding regimen was provided to pullets from 4 wk to 21 wk of age...
October 12, 2016: Poultry Science
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