The green alga Chlamydomonas reinhardtii elaborates two biochemically and morphologically distinct cell walls during its life cycle: one surrounds the vegetative and gametic cell and the other encompasses the zygote. Hydroxyproline-rich glycoproteins (HRGPs) constitute a major component of both walls. We describe the isolation and characterization of a zygote-specific gene encoding a wall HRGP....

In most flowering plants, the apical-basal body axis is established by an asymmetric division of the polarized zygote. In Arabidopsis, early embryo patterning is regulated by WOX homeobox genes, which are coexpressed in the zygote but become restricted to apical (WOX2) and basal (WOX8/9) cells. How the asymmetry of zygote division is regulated and connected to the daughter cell fates is largely...

Background: Digital image processing and analysis are used for computer assisted evaluation of sperm morphology. Sperm head morphology has been identified as a characteristic that can be used to predict a male’s semen quality. On the other hand, zygote competence analysis is an importance tool to select embryo(s) for transfer. The aim of the present study is to determine zygote quality resulted...

The formation of the zygote in cotton is accompanied by marked changes in the number and aggregation of the ribosomes. The zygote is formed approximately 14 hr after pollination but does not divide for some 56-60 hr. Electron microscope studies of the zygote during this period reveal a series of changes in the size and distribution of polysomes which may provide information on this important st...

The oocyte-to-embryo transition transforms a differentiated germ cell into a totipotent zygote capable of somatic development. In C. elegans, several oocyte proteins, including the meiotic katanin subunit MEI-1 and the oocyte maturation protein OMA-1, must be degraded during this transition . Degradation of MEI-1 and OMA-1 requires the dual-specificity YAK-1-related (DYRK) kinase MBK-2 . Here, ...

Auxin is an important plant growth regulator, and plays a key role in apical-basal axis formation and embryo differentiation, but the mechanism remains unclear. The level of indole-3-acetic acid (IAA) during zygote and embryo development of Nicotiana tabacum L. is investigated here using the techniques of GC-SIM-MS analysis, immunolocalization, and the GUS activity assay of DR5::GUS transgenic ...

Zygote intrafallopian transfer (ZIFT) is an assisted reproductive technology [5] (ART) first used in 1986 to help those who are infertile conceive a child. ZIFT is a hybrid technique derived from a combination of in vitro [6] fertilization [7] (IVF) and gamete intrafallopian transfer (GIFT) procedures. Despite a relatively high success rate close to that of IVF, it is not as common as its paren...

The formation of the zygote in cotton is accompanied by marked changes in the number and aggregation of the ribosomes. The zygote is formed approximately 14 hr after pollination but does not divide for some 56-60 hr. Electron microscope studies of the zygote during this period reveal a series of changes in the size and distribution of polysomes which may provide information on this important st...