Microfluidic technology for assisted reproduction.

The physical tools used in assisted reproduction have changed little over several decades. Microfluidics is an emerging technology that allows a fresh examination of the way assisted reproduction is performed. Here we review our work to develop microfluidic devices to perform the functions required in assisted reproduction. These functions include loading/unloading, culture, chemical manipulation, and mechanical manipulation of embryos and oocytes. Basic microfluidic theory and microfluidic device design and operation are discussed. Results are presented for mechanical removal of cumulus cells and for embryo culture. Results suggest that microfluidic systems will lead to improved efficiencies in assisted reproduction.     

Relationships among nutrition and reproduction and relevance for wild animals

This review discusses aspects of feeding ecology, nutrition, and dietary husbandry that are particularly relevant to reproductive success in wild animals. Emphasis has been placed on recently published literature. Special attention has been given to requirements for energy and protein and the unique roles of essential amino acids, essential fatty acids, calcium, phosphorus, zinc, copper, selenium, and vitamins A, C, D, and E. Information has been drawn from research with mammals, birds, reptiles, amphibians, and fish, including the domestic and laboratory species that play such a large role in elucidating mechanisms connecting nutrition and reproduction. Zoo Biol 23:475–487, 2004. © 2004 Wiley-Liss, Inc.     

Ovarian control for assisted reproduction in the domestic cat and wild felids

Of the 37 felid species, all but the domestic cat are classified as threatened with extinction in all or part of their native range. Additionally, the domestic cat is a valuable model for human biomedical research. Propagating some wild felids as well as domestic cat populations serving as human models is a major challenge primarily due to difficulties in transporting animals between facilities to ensure the pairing of genetically matched individuals, behavioral incompatibility between pairs and low fertility. Artificial insemination (AI) and in vitro fertilization/embryo transfer (IVF/ET) are powerful tools for helping manage rare populations. Developing successful assisted reproductive techniques requires knowledge of the female reproductive cycle and precise control of ovarian activity. Successful ovarian stimulation for AI and IVF/ET has been achieved in at least one-third of all cat species. However, sensitivity to a given gonadotropin treatment appears highly species-specific, and poor responses are common, particularly in felid species that exhibit spontaneous ovulations. Furthermore, current gonadotropin regimens have been demonstrated to perturb female reproductive function often leading to reduced fertility. Overall, ovarian response to exogenous hormonal stimulation has been highly variable, and pregnancy success after AI or IVF/ET remains low (<20%) in most species. Therefore, there is an immediate need to develop improved regimens that would allow more predictable ovarian responses in felids. We contend that recent research involving the use of progestins to control the ovary prior to gonadotropin stimulation shows promise for providing consistent ovarian stimulation in felids.     

Uses and limitations of two molecular cytogenetic techniques for the study of arrested embryos obtained through assisted reproduction technology

We studied chromosomal abnormalities in arrested embryos produced by assisted reproductive technology with fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) in order to determine the best technique for evaluating chromosomal aneusomies to be implemented in different situations. We examined individual blastomeres from arrested embryos by FISH and arrested whole embryos by CGH. All of the 10 FISH-analyzed embryos gave results, while only 7 of the 30 embryos analyzed by CGH were usable. Fifteen of the 17 embryos were chromosomally abnormal. CGH provided more accurate data for arrested embryos; however, FISH is the technique of choice for screening in preimplantation genetic diagnosis, because the results can be obtained within a day, while the embryos are still in culture.     

Health of human and livestock conceived by assisted reproduction.

Assisted reproduction is used to resolve infertility problems in human and in breeding programs to generate livestock. Except for gestation length and birth weight, perinatal outcome of children conceived by In Vitro Fertilization is similar to that of spontaneously conceived children. However, large offspring syndrome observed after In Vitro Production in livestock is quite alarming. The distinct parts of assisted reproduction (oocyte maturation, fertilization and culture) have been found to contribute to abnormal fetal growth and development. Genomic imprinting is suggested to be involved in the induction of the aberrant phenotypes observed after assisted reproduction. Furthermore, current knowledge on postnatal health of offspring conceived by assisted reproduction and speculations on potential longterm effects of In Vitro Fertilization will be described.     

DNA分子标记技术在葡萄砧木改良上的应用

葡萄砧木具有抗葡萄根瘤蚜和线虫等土传虫害、抗寒、抗旱、耐盐碱等优良特性,可调控葡萄生长和品质,利用葡萄抗逆砧木进行嫁接栽培已成为葡萄产业发展的必然趋势。因此,开展葡萄砧木改良研究具有十分重要的意义。随着生物技术的发展,DNA分子标记技术已广泛应用于葡萄砧木改良研究,本文对近10年分子标记技术在葡萄砧木品种鉴定、系谱分析、遗传图谱构建等方面的研究应用进行了综述,并指明未来葡萄砧木的研究方向。     

Production of embryos by assisted reproduction in the horse

In vitro embryo production is not yet successful in the horse, largely due to low rates of fertilization in vitro. However, methods to produce embryos from isolated oocytes have been developed. Oocytes may be recovered from living mares by aspiration of the dominant preovulatory follicle by trans-abdominal puncture, and from both preovulatory and immature follicles by trans-vaginal ultrasound-guided puncture. Transfer of in vivo-matured oocytes to the oviducts of bred recipient mares has resulted in good pregnancy rates (75-85%). Little work has been done on transfer of horse oocytes matured in vitro. Recovery rates of immature oocytes from mares in vivo are lower than those for cattle. In addition, work on oocytes recovered from horse ovaries post-mortem has shown that horse oocytes from smaller (< 20 mm diameter) viable follicles may not yet be meiotically competent. Methods for in vitro fertilization and for obtaining adequate numbers of competent immature oocytes from the mare must be developed before in vitro embryo production can become a useful clinical and research procedure in the horse.     

Investigation of assisted fertilization and biology of reproduction by sperm microinjection

Recent success in assisted fertilization mainly depended on the development of sperm microinjection methods: intracytoplasmic sperm injection and subzonal insemination. Some basic mechanisms that under-lie fertilization were revealed by using intracytoplasmic sperm injection. In respect to this, problems of fertility, oocyte activation, formation of pronuclei and practical aspects of intracytoplasmic sperm injection are discussed.     

Control of reproduction by Polycomb Group complexes in animals and plants

In both mammals and plants, Polycomb Repressive Complexes 2 (PRC2) are conserved and appear to be involved in the transition between vegetative or somatic and reproductive state in plants and mammals. In plants at least three different PRC2 control temporal aspects of development, and mutations in PcG cause heterochronies. Such heterochronic mutations affect the transition to flowering. During gametogenesis the Fertilization-Independent Endosperm-MEDEA-PRC2 (FIE-MEA PRC2) complex controls gametogenesis in synergy with a Retinoblastoma-dependent pathway. Several genes of the FIE-MEA pathway are imprinted as shown by their uniparental allele expression in the endosperm, the interface controlling maternal nutrition of the embryo in the seed. Imprinting is also a major feature for genes expressed in the placenta in mammals. Recent data have shown that imprinting in both placenta and endosperm likely share similar mechanisms involving cooperation between the PRC2 complexes and DNA methylation.     

Phenotypic screening and molecular analysis of blast resistance in fragrant rice for marker assisted selection

Experiments were conducted to identify blast-resistant fragrant genotypes for the development of a durable blast-resistant rice variety during years 2012–2013. The results indicate that out of 140 test materials including 114 fragrant germplasms, 25 differential varieties (DVs) harbouring 23 blast-resistant genes, only 16 fragrant rice germplasms showed comparatively better performance against a virulent isolate of blast disease. The reaction pattern of single-spore isolate of Magnaporthe oryzae to differential varieties showed that Pish, Pi9, Pita-2 and Pita are the effective blast-resistant genes against the tested blast isolates in Bangladesh. The DNA markers profiles of selected 16 rice germplasms indicated that genotype Chinigura contained Pish, Pi9 and Pita genes; on the other hand, both BRRI dhan50 and Bawaibhog contained Pish and Pita genes in their genetic background. Genotypes Jirakatari, BR5, and Gopalbhog possessed Pish gene, while Uknimodhu, Deshikatari, Radhunipagol, Kalijira (3), Chinikanai each contained the Pita gene only. There are some materials that did not contain any target gene(s) in their genetic background, but proved resistant in pathogenicity tests. This information provided valuable genetic information for breeders to develop durable blast-resistant fragrant or aromatic rice varieties in Bangladesh.     

How to use molecular marker data to measure evolutionary parameters in wild populations

Estimating the genetic basis of phenotypic traits and the selection pressures acting on them are central to our understanding of the evolution and conservation of wild populations. However, obtaining such evolutionary-related parameters is not an easy task as it requires accurate information on both relatedness among individuals and their breeding success. Polymorphic molecular markers are very useful in estimating relatedness between individuals and parentage analyses are now extensively used in most taxa. The next step in the application of molecular data to wild populations is to use them to derive estimates of evolutionary-related parameters for quantitative traits, such as quantitative genetic parameters (e.g. heritability, genetic correlations) and measures of selection (e.g. selection gradients). Despite their great appeal and potential, the optimal use of molecular tools is still debated and it remains unclear how they should best be used to obtain reliable estimates of evolutionary parameters in the wild. Here, we review the methods available for estimating quantitative genetic and selection parameters and discuss their merits and shortcomings, to provide a tool that summarizes the potential uses of molecular data to obtain such parameters in wild populations.     

Season controlled reproduction of undomesticated animals

The following article is a summary of research on the influence of season on the reproductive processes in undomesticated animals. The results presented below show: a/ an annual hormonal profile of domestic pig and wild boar crossbreed and the antioxidant blood system in the different seasons, b/ the possibility of gonadptropic hormone stimulation in chinchillas which are in diestrus or infertile, c/ the possibility of using bison's semen (collected post mortem from the epididymis) for cryoconservation.     

Charles Thibault and assisted reproduction in France

Charles Thibault was liked by French gynaecologists. There was not a year that Charles Thibault did not attend clinician gynaecology conferences. He made great strides in research on in vitro fertilisation, being the first to perform in vitro fertilised (IVF) oocyte transfers in rabbits. Later, in 1978 the first human pregnancy following IVF was achieved in the UK when Louise Brown was born. In 1980, two French teams,one at the Sèvres hospital and the other at the Clamart University Teaching Hospital, carried out egg retrievals in patients with natural cycles, after determination of the urinary LH peak, under general anaesthesia and by laparoscopy. The Clamart team developed LH SIR, which enabled a more accurate determination of the ideal time for egg collection. In 1983, the same team reported the first ambulatory oocyte retrievals by ultrasound, under local anaesthesia. This new technique did not require general anaesthesia. Finally, in 1983, the rate of births, per transfer, for the Sèvres team rose to 5.31%. 1984 showed considerable improvement: 13.83%. The first step in establishing IVF in France was completed with the Carghese symposium, in September 1984, where Charles Thibault pleaded for animal experimentation before human clinical trials. It was only later that ART developed significantly, necessitating a legislative framework and organisations such as GEFF and FIVNAT.     

rDNA ITS区序列分子标记技术在植物学研究中的应用

在植物学研究中,人们越来越多地采用核糖体DNA内转录间隔区（ITS）作为分子标记。本文对近10年来rDNA ITS序列在植物系统发育、分类与鉴定、种质资源以及病虫害的鉴定与防治中的应用等方面的研究进展进行了综述,并对ITS序列的应用前景进行了初步探讨。     

Chemical and bio-chemical reactions assisted by pervaporation technology

Abstract

Since several decades ago, the application of pervaporation (PV) technology has been mainly aimed at the separation of different types of water-organic, organic-water and organic–organic mixtures, reaching its large-scale application in industry for the dehydration of organics. Today, the versatility and high selectivity toward specific compounds have led its consideration to other types of application such as the assisted chemical and bio-chemical reactions. The focus of this review is to provide a compelling overview on the recent developments of PV combined with chemical and bio-chemical reactions. After a general introduction of PV and its theoretical background, particular emphasis is given to the results obtained in the field for different reactions considered, identifying the key features and weak points of PV in such particular applications. Furthermore, future trends and perspectives are also addressed according to the latest literature reports.