Worldwide, termites are one of few social insects. In this research, the stages embryonic development in parthenogenetic and sexual eggs Reticulitermes aculabialis R. flaviceps were observed described. flaviceps, egg FF FM groups happened during early phases development, whereas aculabialis, appeared mainly late phase development. The variance number micropyles between colony type was statistic...

We have studied the localisation of mRNAs in full-grown Xenopus laevis oocytes by injecting fluorescent RNAs, followed by confocal microscopy of the oocyte cortex. Concentrating on RNA encoding the Xenopus Nanos homologue, nanos1 (formerly Xcat2), we find that it consistently localised into aggregated germ plasm ribonucleoprotein (RNP) particles, independently of cytoskeletal integrity. This im...

Paper birch (Betula papyrifera Marsh) seedlings were grown in a greenhouse in either subsoil or topsoil in factorial combination with two fertilization and drought regimes to investigate how different soil environments and nutrient availability drive belowground partitioning between growth, secondary metabolism and ectomycorrhizal (EM) associations, and impact drought tolerance of paper birch. ...

The effects of nitrogen (N) addition on productive and physiological traits of Triticumdicoccum were assessed under two N levels (0, unfertilized, and 90 kg N ha−1) in fieldconditions, in two growing seasons. In the study case, the N supply (90 kg N ha−1) was appliedin three-split applications (20% at pre-plant stage, 40% at tillering stage, 40% at stemelongation). In unfertilized conditions, t...

HEN Habrobracon eggs are X-rayed at metaphase I and subsequently fertiw l i z e d , the decreased hatchability is attributed to dominant lethal mutation, in the same sense in which the term is used when sperm are irradiated. This is justified by WHITING'S demonstration (1946, 1948, 1949, 1950, 1955) that cytoplasmic injury is not lethal a t the doses employed. In unfertilized eggs, which develo...

Taxol blocks the migrations of the sperm and egg nuclei in fertilized eggs and induces asters in unfertilized eggs of the sea urchins Lytechinus variegatus and Arbacia punctulata. Video recordings of eggs inseminated in 10 microM taxol demonstrate that sperm incorporation and sperm tail motility are unaffected, that the sperm aster formed is unusually pronounced, and that the migration of the e...

The objective was to evaluate the effect of the first artificial insemination (AI) on the number of viable and degenerated embryos, total embryos and unfertilized oocytes, and fertilization rate in Holstein donor cows. Cows (n=22) and heifers (n=50) were synchronized by the Crestar (Intervet International B.V., Boxmeer, Holland) protocol where 3 mg of norgestomet are implanted subcutaneously in...

Sea urchin eggs are arrested in G1 of the first mitotic cell cycle. Fertilization triggers release from G1 arrest and the onset of DNA synthesis about 20 minutes later, even when protein synthesis is blocked. Here we describe extracts from eggs and S-phase embryos that reproduce this stage-specific pattern of DNA synthesis. Fertilized egg extracts formed nuclear membranes around decondensed Xen...

A special feature of eggs of several species of annelids and molluscs is the formation of a polar lobe at stage-specific intervals during the cleavage phase. In the scaphopod Dentalium, a polar lobe develops at the first, the second and the third cleavage (Wilson, 1904). The cytoplasm set apart in the polar lobes is ultimately confined to the D blastomere and its derivative cells. Wilson observ...