According to reviews (Tyler, 1955; Rothschild, 1956), chemotaxis of spermatozoa towards eggs has not been unequivocally demonstrated in animals. However, more recently, Suzuki (i96ia-c) has claimed that, in several species of Japanese bitterlings, the spermatozoa are attracted to a substance found in the egg micropyle. Suzuki's experiments, as well as earlier ones that aimed to prove or disprov...

The impact of cold radiofrequency air plasma on the wetting properties and water imbibition of beans (Phaseolus vulgaris) was studied. The influence of plasma on wetting of a cotyledon and seed coat (testa) was elucidated. It was established that cold plasma treatment leads to hydrophilization of the cotyledon and tissues constituting the testa when they are separately exposed to plasma. By con...

Feces from southern brown bandicoots, Isoodon obesulus, inhabiting the Perth metropolitan area were examined using fecal flotation and light microscopy, and were frequently found to contain oocysts (10/24; 42%). To enable formal description of the proposed new Eimeria species, i.e., Eimeria quenda n. sp., fecal oocysts from 1 juvenile male I. obesulus were allowed to sporulate in 2% potassium d...

Oocysts of Eimeria banffensis Lepp, Todd, and Samuel, 1972, Eimeria cryptobarretti sp. n., Eimeria princepsis sp. n., and Eimeria calentinei sp. n. are described from the Colorado pika, Ochotona princeps, collected from 3 mountain sites in Colorado. Subspherical oocysts of E. banffensis measure 23 to 34 by 18 to 25 p (mean 27.6 by 23.0 p ) with ovoid sporocysts 10 to 16 by 7 to 10 p (mean 12.5 ...

The aim of this study is to describe the ultrastructural changes of the egg apparatus associated with fertilisation of the natural tetraploid Trifolium pratense. The pollen tube enters one of the synergids through the filliform apparatus from the micropyle. Before the entry of the pollen tube into the embryo sac, one of the synergids begins to degenerate, as indicated by increased electron dens...

The Notch signaling pathway is a highly evolutionarily-conserved cell-cell signaling pathway that regulates many events during development. It plays a pivotal role in the regulation of fundamental cellular processes, such as cell proliferation, stem cell maintenance, and differentiation during embryonic and adult development. However, functions of Notch signaling in Aedes aegypti, the major mos...

determination of the accurate time of egg stripping after ovulation has been regarded as one of the most important factors in the successful reproduction of caspian brown trout(salmo trutta caspius). to determine the best time for egg stripping after ovulation and over- ripening of the oocyte in the caspian brown trout , the eggs of fish were retained in the coelomic cavity of females at 7 ± 6°...

A new genetic interpretation of self-sterility as manifested in Sicotiana alata Lk. and Otto var. grandijiora Comes and Sicotiana forgetiana Hort. (Sand.), or their hybrids, has been proposed recently (EAST and M ~ N G E L S DORF 192.5). The detailed evidence on which this interpretation rests i< given in the present paper. Self-sterility appears to behave as a simple recessive when the,e speci...

Females homozygous for the otu7 allele produce ovarian tumours, as well as egg chambers that reach a relatively late stage of development. Mutant ovarian nurse cells contain giant polytene chromosomes. These are transcriptionally active, and RNA is transported to the oocyte through ring canals, although at reduced rate. Vitellogenic oocytes are endocytotically active. Protein (alpha yolk) spher...