Valproate, thalidomide and ethyl alcohol alter the migration of HTR-8/SVneo cells

Background  

Valproate, thalidomide and alcohol (ethanol) exposure during the first trimester of pregnancy is known to cause several developmental disorders. All these teratogens are known to pass the placental barrier and interfere directly with the normal development of the fetus. However, these teratogens also alter the formation and function of the placenta itself which may in turn affect the proper nourishment and development of the fetus. Optimum development of the placenta requires adequate invasion of trophoblast into the maternal uterine tissues. Changes in the migratory behavior of trophoblast by maternal exposure to these teratogens during placentogenesis may therefore alter the structure and function of the placenta.     

Biotechnology of the Banana: A Review of Recent Progress

Abstract: A number of biotechnological tools have been developed which could help breeders to evolve new plant types to meet the demand of the food industry in the next century. Available techniques for the transfer of genes could significantly shorten the breeding procedures and overcome some of the agronomic and environmental problems which would otherwise not be possible through conventional methods. In vitro protocols have been standardized to allow commercially viable propagation of desired clones of Musa. An overview of the regeneration of banana by direct and indirect organogenesis, and somatic embryogenesis is presented in this article. In addition, the use of several other biotechnological techniques to enrich the genome of banana, such as selection of somaclonal variants, screening for various useful characteristics, cryopreservation, genetic transformation and molecular genetics are reviewed. In conclusion, the improvement of banana through modern biotechnology should help ensure food security by stabilizing production levels in sustainable cropping systems geared towards meeting domestic and export market demands.     

Isoelectric focusing studies of aldehyde dehydrogenases from mouse tissues: variant phenotypes of liver, stomach and testis isozymes

Isoelectric focusing techniques (IEF) were used to examine the tissue distribution and genetic variability of aldehyde dehydrogenases (AHDs) from inbred strains of mice. Twelve zones of AHD activity were resolved which were differentially distributed between tissues. Liver extracts exhibited highest activity for most enzymes, with the exception of isozymes found in stomach (AHD-4) and testis (AHD-4 and AHD-6). Genetic variants for AHD-1 (liver mitochondrial isozyme) and AHD-4 (stomach isozyme) were examined from inbred strains and F1 hybrid animals. The results were consistent with dimeric subunit structures (designated as A2 and D2 isozymes respectively). IEF patterns for activity variants of testis-specific AHD-6 were identical, with 3-banded phenotypes being observed. pI values for the AHD forms as well as for aldehyde oxidase and xanthine oxidase isozymes, which stain in the absence of coenzyme, were reported.     

Methyl laurate and 6-benzyladenine promote the germination of somatic embryos of a hybrid rose

Globular stage somatic embryos were induced in callus cultures of Rosa Heritage 2 Alister Stella Gray on medium containing 13.5 µM 2,4-dichlorophenoxyacetic acid (2,4-D) and developed to the cotyledonary stage on medium containing 9 µM 2,4-D. Cotyledonary-stage embryos were transferred to germination media with or without 1.5 µM 6-benzyladenine (BA) and with or without 44 µM methyl laurate (Mela). BA and Mela both promoted the development of shoots and roots and increased the frequency of bipolar germinations. An average of 56.5% (SEdž.1%) embryos on medium containing both BA and Mela underwent bipolar germinations compared with less than 20% in treatments where either or both were excluded. The effectiveness of BA and Mela was reduced if Mela was included in the development medium or if the concentration of salts and vitamins in the germination media was sub-optimal. There was evidence that growth at one pole of the somatic embryo promoted development at the other.