RESUMEN
Catkin buds of Salix alaxensis from interior Alaska were analyzed for water and lipid content and fatty acid composition throughout the year. Water content was significantly correlated with environmental temperature, but lipid content was not. Linoleic acid (18:2) and arachidic acid (20:0) were predominant in the lipids of whole catkins.Of the 27 different fatty acids found in all weekly samples, 11 showed pronounced seasonal variation, most of which occurred during catkin development and flowering in spring. During winter, only the amount of linoleic acid in the catkins was significantly negatively correlated with change in ambient temperature.Histological and chemical analyses of the catkin florets and catkin scales revealed that 99% of the linoleic acid was located in the florets primarily in the form of triglycerides while 94% of the arachidic acid was located in the catkin scale primarily as wax esters. While the linoleic acid in the triglycerides of the meristematic florets probably provides an energy source for the developing catkins, the large amounts of arachidic acid located in the catkin scales probably serves to prevent dessication of the catkins during the long, cold and dry arctic winters.
RESUMEN
Trisomy 7 mosaicism was detected prenatally in cultured amniocytes but not in fetal lymphocytes. The child that was born had pigmentary changes of the skin and facial asymmetry suggestive of a chromosomal mosaicism. Skin fibroblasts were studied and trisomy 7 mosaicism was confirmed. At 3 years of age the boy had developed mentally within normal limits. However, dysmorphic findings include sparse hair, short left palpebral fissure, ptosis of the left eyelid, strabismus, enamel dysplasia, low-set and posteriorly rotated ears and undescended testes. These findings share some common features with previously reported cases of trisomy 7 mosaicism.