The roles of cell polarity and the first asymmetric cell division during early embryogenesis in apical-basal cell fate determination remain unclear. Previously, a novel Brassica napus microspore embryogenesis system was established, by which rape exine-dehisced microspores were induced by physical stress. Unlike traditional microspore culture, cell polarity and subsequent asymmetric division ap...

introdouction: age estimation is an important issue in forensics, particularly for treatment planning and determining patients’ rights. radiographic evaluation of the third molar developmental stage is a significant criterion for age estimation. the pattern of tooth development is largely heritable and varies from race to race. the objective of this study was to radiographically examine and com...

Background: The aim of this study was evaluation of developmental rate and Bax, Bcl-2 and ErbB4 genes expression following re-vitrification in compact and early blastocysts stages. Materials and Methods: 5-8 cell embryos were collected from female mature mice, 60-62 hours post hCG injection. The embryos were divided to five groups including: fresh, vitrified at 5-8 cells, vitrified at blastocys...

the life history of enochrus quadripunctatus herbst was studied in the laboratory. the duration of each developmental stage, larval behavior, and preimaginal mortality rate were determined. it takes the insect a total of 43 days from hatching to reach the adult stage, with a high mortality rate in the first stadium. the mortality rate decreases as the beetle passes through the immature stages. ...

Hop latent viroid (HLVd) is not transmissible through hop generative tissues and seeds. Here we describe the process of HLVd elimination during development of hop pollen. HLVd propagates in uninucleate hop pollen, but is eliminated at stages following first pollen mitosis during pollen vacuolization and maturation. Only traces of HLVd were detected by RT-PCR in mature pollen after anthesis and ...

Among the >200 members of the leucine-rich repeat receptor kinase family in Arabidopsis thaliana, only a few have been functionally characterized. Here, we report a critical function in anther development for the SOMATIC EMBRYOGENESIS RECEPTOR KINASE1 (SERK1) and SERK2 genes. Both SERK1 and SERK2 are expressed widely in locules until stage 6 anthers and are more concentrated in the tapetal cell...

1- introduction crop development is qualitative changes planned that led the plant to ripening. factors such as water available, nitrogen and photosynthetic materials are affected growth and development. under irrigated conditions expected that all of factors except climate elements be controlled. thus, only climate elements able to change of plant growth and development and under these conditi...

The technique of isolated microspore culture for the production of haploid plants is well standardized for many species of Brassica, some of which are important oilseed or vegetable crops. It offers an excellent experimental system for improvement of Brassica crops and study of cell differentiation during shift from gametophytic to sporophytic development. The haploids raised from microspores a...

This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity delayed embryo development, leading to aborted embryos that could be classified as early curled cotyledons. The embryo-lethal phenotype of psp1 mutants could be complemented with PSP1 cDNA unde...