BACKGROUND Pregnancy is widely viewed as dependent upon an intimate dialogue, mediated by locally secreted factors between a developmentally competent embryo and a receptive endometrium. Reproductive success in humans is however limited, largely because of the high prevalence of chromosomally abnormal preimplantation embryos. Moreover, the transient period of endometrial receptivity in humans u...

Preimplantation genetic diagnosis (PGD) involves testing for specific genetic conditions prior to the implantation [5] of an embryo in the uterine wall. This form of genetic screening has been made possible by the growth of in-vitro fertilization [6] (IVF) technology, which allows for the early stages of development to occur in a laboratory dish rather than in vivo [7]. The purpose of PGD is to...

BACKGROUND The development of the mouse zygote following fertilization in vitro in a KSOM-type medium containing either L-glutamine or glycyl-L-glutamine has been examined, and compared with the development of mouse zygotes produced by natural fertilization. METHODS Mouse IVF, embryo culture and embryo transfer. RESULTS Fertilization rates, development to the blastocyst stage, implantation ...

The cellulose synthase-like proteins are a large family of proteins in plants thought to be processive polysaccharide beta-glycosyltransferases. We have characterized an Arabidopsis mutant with a transposon insertion in the gene encoding AtCSLA7 of the CSLA subfamily. Analysis of the transmission efficiency of the insertion indicated that AtCSLA7 is important for pollen tube growth. Moreover, t...

DNA methylation (5-methylcytosine) in mammalian genomes predominantly occurs at CpG dinucleotides, is maintained by DNA methyltransferase1 (Dnmt1), and is essential for embryo viability. The plant genome also has 5-methylcytosine at CpG dinucleotides, which is maintained by METHYLTRANSFERASE1 (MET1), a homolog of Dnmt1. In addition, plants have DNA methylation at CpNpG and CpNpN sites, maintain...

Despite numerous advances in cell biology, genetics, and developmental biology, cancer origin has been attributed to genetic mechanisms primarily involving mutations. Embryologists have expressed timidly cancer embryological origin with little success in leveraging the discussion that cancer could involve a set of conventional cellular processes used to build the embryo during morphogenesis. Th...

The teleost fish embryo is particularly sensitive to petroleum hydrocarbons (polycyclic aromatic hydrocarbons, PAHs) at two distinct stages of development. The first is early during cleavage stages when PAHs alter normal signaling associated with establishment of the dorsal-ventral axis. This disruption involves the Wnt/β-catenin pathway and results in hyperdorsalized embryos that do not surviv...

Preimplantation genetic diagnosis (PGD) involves testing for specific genetic conditions prior to the implantation [5] of an embryo in the uterine wall. This form of genetic screening has been made possible by the growth of in-vitro fertilization [6] (IVF) technology, which allows for the early stages of development to occur in a laboratory dish rather than in vivo [7]. The purpose of PGD is to...

The even-skipped (eve) promoter contains a series of enhancers that control the expression of different segmentation stripes in the Drosophila embryo. The stripe 3 enhancer is located 1.7 kb upstream of the stripe 2 enhancer. Here we demonstrate that these enhancers must be physically separated by a minimum distance for proper stripe expression. When they are directly coupled in either orientat...

Exogenously applied retinoic acid given at the early stages of gastrulation causes abnormal development of the caudal midbrain and anterior hindbrain in vertebrate embryos. We describe the limits of the brain regions that are affected using neuroanatomical criteria in the zebrafish embryo. Analysis of the reticulospinal complex shows that the Mauthner cell, which normally differentiates in rhom...