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关键词： fecundity   pairing success   reproductive strategies   reproductive success   size-assortative mating  

摘要： The reproductive biology of Hyalella longistila (Faxon, 1876), a freshwater amphipod found in streams in southeastern Brazil, was investigated. We assessed body-size relationships between paired and unpaired males and females as well as the egg stage, fecundity, relationship between number of eggs and their stage, number of eggs and female size, and pairing and reproductive success. A positive Spearman rank correlation was observed between the cephalothorax length (CL) of paired males and females. The mean CL of paired males and females was positively related, indicating a size-assortative mating. The mean fecundity was 12.88 +/- 2.00 eggs per female, with peaks in August 2012 and September 2012, with 16.82 and 15.08 eggs per female, respectively. The developmental stage and the number of eggs found on the brood pouch were negatively correlated, indicating that as the embryo developed, fewer eggs remained in the egg pouch (marsupium). Higher values for male pairing success were observed for size classes between 0.59 and 0.67 mm, and both sexes presented higher values for reproductive success between 0.63 and 0.68 mm. Our results could support conservation practices or even studies using such amphipods as model organisms.

关键词： early life stress   functional gastrointestinal disorders   therapeutic approaches   translational research   visceral pain  

摘要： Background Epidemiological studies show that females are twice as likely to receive a diagnosis of irritable bowel syndrome (IBS) than their male counterparts. Despite evidence pointing to a role for sex hormones in the onset or exacerbation of IBS symptoms, the mechanism by which ovarian hormones may predispose women to develop IBS remains largely undefined. On the other hand, there is a growing body of research showing a correlation between reports of early life stress (ELS) and the diagnosis of IBS. Current treatments available for IBS patients target symptom relief including abdominal pain and alterations in bowel habits, but are not directed to the etiology of the disease. Purpose To better understand the mechanisms by which sex hormones and ELS contribute to IBS, animal models have been developed to mirror complex human experiences allowing for longitudinal studies that investigate the lifelong consequences of ELS. These preclinical models have been successful in recapitulating ELS-induced visceral pain. Moreover, in female rats the influence of cycling hormones on visceral hypersensitivity resembles that seen in women with IBS. Such studies suggest that rodent models of ELS may serve as pivotal tools in determining (i) the etiology of IBS, (ii) novel future treatments for IBS, and (iii) improving individualized patient care. The current review aims to shed light on the progress and the challenges observed by clinicians within the field of gastroenterology and the preclinical science aimed at addressing those challenges in an effort to understand and more efficiently treat functional gastrointestinal disorders (FGIDs) in both children and adults.

摘要： One of the goals of synthetic biology is to develop programmable artificial gene networks that can transduce multiple endogenous molecular cues to precisely control cell behavior. Realizing this vision requires interfacing natural molecular inputs with synthetic components that generate functional molecular outputs. Interfacing synthetic circuits with endogenous mammalian transcription factors has been particularly difficult. Here, we describe a systematic approach that enables integration and transduction of multiple mammalian transcription factor inputs by a synthetic network. The approach is facilitated by a proportional amplifier sensor based on synergistic positive autoregulation. The circuits efficiently transduce endogenous transcription factor levels into RNAi, transcriptional transactivation, and site-specific recombination. They also enable AND logic between pairs of arbitrary transcription factors. The results establish a framework for developing synthetic gene networks that interface with cellular processes through transcriptional regulators.

摘要： The remarkable stoichiometric flexibility of hydroxyapatite (HAp) enables the formation of a variety of charged structural sites at the material's surface which facilitates bone remodeling due to binding of biomolecule moieties in zwitterionic fashion. In this paper, we report for the first time that an optimized biomedical grade silicon nitride (Si3N4) demonstrated cell adhesion and improved osteoconductivity comparable to highly defective, non-stoichiometric natural hydroxyapatite. Si3N4's zwitterionic-like behavior is a function of the dualism between positive and negative charged off-stoichiometric sites (i.e., N-vacancies versus silanols groups, respectively). Lattice defects at the biomaterial's surface greatly promote interaction with positively- and negatively-charged functional groups in biomolecules, and result in the biologically effective characteristics of silicon nitride. These findings are anticipated to be a starting point for further discoveries of therapeutic bone-graft substitute materials.

关键词： RECYCLING conferences   ANIMAL diversity   SCIENTIFIC experimentation  

摘要： The article offers information on the 'Improving Experimental Approaches in Animal Biology: Implementing the 3Rs' meeting to be held in London, England in June 2016 based on replacement, reduction and refinement (3R) for improving experimental approaches in animal biology.

关键词： Zika virus   epidemiology   pathology   transmission   animal model  

摘要： Zika virus (ZIKV) was first described in 1947, and became a health emergency problem in 2016 when its association with fetal microcephaly cases was confirmed by Centers for Disease Control and Prevention (CDC) in the United States. To date, ZIKV infection has been documented in 66 countries. ZIKV is recognized as a neurotropic virus and numerous diseases manifested in multiple neurological disorders have been described, mainly in countries that have been exposed to ZIKV after the 2007 outbreak in the Federated States of Micronesia. The most dramatic consequence of ZIKV infection documented is the abrupt increase in fetal microcephaly cases in Brazil. Here, we present an update of the published research progress in the past few months. (C) 2016 Wiley Periodicals, Inc.

关键词： Invertebrates, Marine   Aging   Vascular Biology   Germ Cells   Fertility   Blood Vessels   Regeneration   Regenerative   Ascidians   Model Studies  

摘要： Colonial ascidians are marine invertebrate chordates that are the closest invertebrate relative to the vertebrates. Colonies of Botryllus schlosseri undergo a continuous asexual reproduction process that involves the regeneration of entire new bodies, which include all somatic and germline tissues. This adult regenerative process depends on signaling pathways known to regulate the formation of tissues and organs during embryonic development. The formation of gonads within regenerated bodies depends on migration and homing of germ cell precursors to niches within the developing bodies, and Botryllus colonies can cycle between fertile and infertile states. The vasculature that connects all individuals within the colony is highly regenerative, and is a valuable tool for the study of angiogenesis in adult blood vessels. The tremendous regenerative capacity of the vasculature even results in regeneration of entire new bodies solely from fragments of blood vessels upon surgical removal of all bodies. The mechanism underlying this regeneration of whole bodies is not well understood, but appears to depend on proliferation of circulating, blood borne cells. Because of all of these features, colonial ascidians are ideal model organisms for the study of germ cell migration, fertility, vascular biology and regeneration.

关键词： 小鼠   转基因   基因敲除   基因敲入  

摘要： 模式动物在生命科学研究中广泛应用,其中小鼠模型是在生命科学研究中使用最为广泛的模式生物。近年来,小鼠基因改造技术的发展,有力推动了生命科学研究的进展。因此,有必要在教学过程中广泛推广介绍该技术,方便科研工作者应用。总结了几种基因改造技术的技术原理以及应用,同时介绍了该领域最新的技术进展。

关键词： 培养基   动物饲料   微生物   菌落总数   霉菌  

摘要： 试验探讨不同培养基对动物饲料微生物检验结果的影响,为饲料微生物学检验的培养基选择提供依据。分别采用3种菌落总数培养基和3种霉菌培养基,检测SPF大小鼠生长繁殖饲料、SPF豚鼠生长繁殖饲料、兔维持饲料、犬维持饲料和猴维持饲料中的菌落和霉菌总数。无论是实验室自制还是市购成品培养基,5种饲料用3种不同菌落总数培养基,3种不同霉菌培养基检测的检验结果均合格,且各培养基间所测得的菌落总数及霉菌总数经统计学分析,无统计学差异(P>0.05)。在相同试验条件和范围下,尽管采用不同培养基,都不会对动物饲料的菌落总数及霉菌总数检验结果造成明显影响。