This study describes the initial phases of wing morphogenesis of Megoura viciae Buckton (Homoptera Aphididae). We evaluated the development of wing buds in males (winged) and parthenogenetic females (presumed to become wingless) of M. viciae from birth to 4 instar. Wing bud epithelium in males is initially simple, becoming bistratified and then progressing to stratify. Mitotic activity is more ...

Expression of Lunatic fringe mRNA was studied during feather morphogenesis and showed three stages of dynamic expression pattern. (1) Lunatic fringe was first expressed in the epithelium as a ring bordering the feather primordium when it was initially induced. (2) Shortly after, it showed a polarized pattern, first toward the lateral side of the feather primordium and then made a 90 degrees C s...

We compared microsporogenesis and flower development in Eucalyptus urophylla × E. tereticornis. In this study, although microsporogenesis and cytokinesis occurred simultaneously during meiosis of pollen mother cells, we observed a strong asynchronism in different anthers from a flower bud. The developmental period of microsporogenesis in anthers originated from the long thrum before the short t...

Given the growth rate throughout an embryonic rudiment, one can calculate how its parts must shift as it gets bigger, and so plot fate maps showing their future positions. The calculation is done here for the chick wing-bud from stage 18 to 25, using published data for mitotic index and cell packing density, and new measurements of size and shape. Two main findings are: (1) the wing-bud in this...

This study highlights the dynamic nature of the mesenchymal cells during tooth development from the bud to the bell stage. Condensing mesenchymal cells, labelled on either side of the developing tooth bud, move toward the presumptive roots forming an arc of cells under the dental papilla. These labelled cells take part in formation of the dental follicle, which contributes to both the tooth and...

Mll, Brg1 and Brm are vertebrate homologues of Drosophila trithorax group (trxG) genes. We isolated chicken Mll cDNA clones, and examined patterns of Mll, Brg1 and Brm expression in chick embryos. All three genes were expressed from embryonic stage 2 onwards. Mll transcripts were just detectable in all tissues by in situ hybridization, with highest level in dorsal neural tube and notochord. Brg...

in order to study the effect of different concentrations of salicylic acid in two commercial apricotcultivars of shahrood namely ‘shahrood 41’ and ‘jaffari’, under cold stress, a factorial experiment wasconducted in a randomized complete block design with three replications in 2012 at the agriculturalresearch center of shahrood city. the test had four factors including: sa with three levels (0....

The localization of three carbohydrate antigens, Lex, Ley, and sialylated Lex-i, which are closely related to stage-specific embryonic antigen 1, in the lung of developing human embryos was investigated using specific monoclonal antibodies. In the 38-day-old embryo, when the primitive lung bud has appeared and developed into two lung sacs, only Ley antigen was specifically positive in the proli...