REPRODUCTIVE SUCCESS OF FUCUS VESICULOSUS (PHAEOPHYCEAE) IN THE BALTIC SEA

Marine organisms colonizing brackish habitats such as the Baltic Sea must cope with the negative effects of low salinities on reproductive success because these may reduce gamete viability and/or increase polyspermy. Reproductive characteristics of the marine seaweed Fucus vesiculosus L. were studied in several brackish habitats, particularly in the northern Baltic Sea, to understand its ability to reproduce where few other marine species survive. Polyspermy and fertilization success were variable at the boundary of the continuous distribution of F. vesiculosus in the Baltic Sea, and polyspermy was high (10%–30%) when fertilization was successful. A strong female bias (80%–86%, ca. 5.5:1) was found at the northernmost limit of Baltic F. vesiculosus. Electrophysiological studies showed that many eggs have a high input resistance (519 ± 150 MΩ[mean ± SE, n = 14] at Drivan, 1995), which may be helpful in preventing polyspermy in this brackish habitat. The polyspermy block remains sodium-dependent in the northern Baltic. Sperm bound quickly to northern Baltic eggs in natural water, but fertilization was delayed compared to marine F. vesiculosus. A subset of northern Baltic eggs studied during an optimal reproductive period (7–11 July 1995) had a membrane potential (E_m) of ca. −100 mV and an effective fertilization potential (FP) of ca. 2 min with a plateau of −25 mV, but repolarized too rapidly for the FP to be protective. Pronuclear migration and cell wall secretion occurred more slowly in Baltic than in marine zygotes. The reproductive success of theseboundary populations may be dependent upon windows of opportunity when there are favorable combinations of the levels of salinity, water motion, population density, and sex ratio. These factors and the short duration of the reproductive season in the northern Baltic Sea may result in reproductive failure in some years.     

Drawing the line on in vitro gametogenesis

In vitro gametogenesis (IVG) might offer numerous research and clinical benefits. Some potential clinical applications of IVG, such as allowing opposite-sex couples experiencing infertility to have genetically related children, have attracted support. Others, such as enabling same-sex reproduction and solo reproduction, have attracted significantly more criticism. In this paper, we examine how different ethical principles might help us to draw lines and distinguish between ethically desirable and undesirable uses of IVG. We discuss the alleged distinction between therapeutic and non-therapeutic uses of assisted reproduction in the context of IVG, and show how it is both problematic to apply in practice and theoretically dubious. We then discuss how the ethical principles of reproductive justice and beneficence apply to IVG for opposite-sex reproduction, same-sex reproduction, and solo reproduction. We suggest that these principles generate strong reasons for the use of IVG for opposite-sex and same-sex reproduction, but not for solo reproduction.     

果子狸繁殖期行为的观察

描述了果子狸在繁殖期表现出的１７种子体为、１４种神群行为和交配模式。个体行为包括侧卧、叭、蹲、静立、双脚站立、食粪、理毛、抓痒、嗅闻、标记,发情叫、雄性鸣咽声、舔阴茎、咬阴部、食交配栓;社会行为包括仪式化格斗、雌性雄必与的抵抗、打斗、依偎、同性或异性之间彼此舔毛、雄性嗅闻雌性阴部及尿液、舔雌性阴部和错爬胯,交配行为主要在夜间进行,其交配模式为无锁结（可能）多次插入、插入后抽动、一次、性射精并在射精     

Analysis of birth defects among children 3 years after conception through assisted reproductive technology in China

BACKGROUND : Previous studies inconsistently suggest that assisted reproduction technology (ART) may increase the risk of birth defects in children. METHOD(S) : Live birth infants, conceived by in vitro fertilization fresh embryo transfer (IVF), intracytoplasmic sperm injection fresh embryo transfer (ICSI), or frozen‐thawed embryo transfer (FET) in Reproductive Center of Tongji Hospital (Wuhan, China) between 1997 and 2008, were followed up at birth and after 3 years. Preterm pregnancy, multiple pregnancy, sex ratio (male/female), congenital malformation were compared. RESULT(S) : A total of 4,236 children were born after ART (IVF 2,543, ICSI 908, FET 785). Compared with IVF, the rate of preterm pregnancy and sex ratio in ICSI were lower (p < 0.05); the rate of multiple pregnancy in ICSI and FET were all lower than IVF (p < 0.05). Congenital defects were comparable in all groups at birth. In total, 2,908 children participated in the second follow‐up from 34 months to 60 months with an average of 40 months, and the cases of birth defects had doubled (3 years: 5.16%, birth: 2.22%). The birth defect rate in boys conceived through ICSI was significantly higher than the IVF group after 3‐year follow‐up (ICSI boys: 8.62%, IVF boys: 5.21% [p < 0.05]), even though there was no significant difference at birth. CONCLUSION(S) : Compared with IVF, FET may not increase risk of birth defects. Children conceived through ICSI, especially males, had higher rates of congenital malformations that were inapparent at birth. So longitudinal monitoring may provide insights into the risks of ART. Birth Defects Research (Part A) 97:744–749, 2013. 2013. © 2013 Wiley Periodicals, Inc.     

THE ACCUMULATION OF REPRODUCTIVE INCOMPATIBILITIES IN AFRICAN CICHLID FISH

The rate at which different components of reproductive isolation accumulate with divergence time between species has only been studied in a limited, but growing, number of species. We measured premating isolation and hybrid inviability at four different ontogenetic stages from zygotes to adults in interspecific hybrids of 26 pairs of African cichlid species, spanning the entire East African haplochromine radiation. We then used multiple relaxed molecular clock calibrations to translate genetic distances into absolute ages to compare evolutionary rates of different components of reproductive isolation. We find that premating isolation accumulates fast initially but then changes little with increasing genetic distance between species. In contrast, postmating isolation between closely related species is negligible but then accumulates rapidly, resulting in complete hybrid inviability after 4.4/8.5/18.4 million years (my). Thus, the rate at which complete intrinsic incompatibilities arise in this system is orders of magnitude lower than rates of speciation within individual lake radiations. Together these results suggest divergent ecological adaptations may prevent populations from interbreeding and help maintain cichlid species diversity, which may be vulnerable to environmental degradation. By quantifying the capacity to produce viable hybrids between allopatric, distantly related lineages our results also provide an upper divergence time limit for the “hybrid swarm origin” model of adaptive radiation.     

The utility of nuclear magnetic resonance spectroscopy in assisted reproduction

Infertility affects approximately 15–20% of individuals of reproductive age worldwide. Over the last 40 years, assisted reproductive technology (ART) has helped millions of childless couples. However, ART is limited by a low success rate and risk of multiple gestations. Devising methods for selecting the best gamete or embryo that increases the ART success rate and prevention of multiple gestation has become one of the key goals in ART today. Special emphasis has been placed on the development of non-invasive approaches, which do not require perturbing the embryonic cells, as the current morphology-based embryo selection approach has shortcomings in predicting the implantation potential of embryos. An observed association between embryo metabolism and viability has prompted researchers to develop metabolomics-based biomarkers. Nuclear magnetic resonance (NMR) spectroscopy provides a non-invasive approach for the metabolic profiling of tissues, gametes and embryos, with the key advantage of having a minimal sample preparation procedure. Using NMR spectroscopy, biologically important molecules can be identified and quantified in intact cells, extracts or secretomes. This, in turn, helps to map out the active metabolic pathways in a system. The present review covers the contribution of NMR spectroscopy in assisted reproduction at various stages of the process.     

Embryo Quality May Be Associated With Serum Inhibin B Levels but Not With Serum or Follicular Fluid Levels of Other Components of the Activin–Follistatin–Inhibin Axis

ObjectiveWe investigated the potential associations of embryo quality with serum and/or follicular fluid (FF) concentrations of the molecules of the activin–follistatin–inhibin (AFI) axis and antimüllerian hormone and aimed to identify molecules that could predict a positive assisted reproductive technology (ART) outcome.MethodsIn this cross-sectional study, we measured AFI hormone and antimüllerian hormone levels in the serum and FF of follicles (n = 101) obtained from healthy oocyte donors who underwent an assisted reproductive technology course (n = 32). After egg retrieval, embryos were characterized as good or bad quality according to the European Society of Human Reproduction and Embryology criteria. Women were divided into 3 groups (<50%; 50%-66.7%; and >66.7%) according to the percentage of good quality embryos obtained.ResultsThere was no difference between good and bad quality embryos in any of the molecules measured in FF. Moreover, there was no difference in the parameters measured in the serum among women according to the percentage of good quality embryos (ie, suitable for transfer or freezing) except for inhibin B, which tended to increase along with a good quality embryo rate (55.6 ± 7.9 vs 95.3 ± 14.3 vs 113.9 ± 36.9; P = .045).ConclusionsAmong the molecules of the AFI axis, only serum but not FF inhibin B levels were marginally associated with good quality embryo rates.