Post‐glacial history and introgression in Abies (Pinaceae) species of the Russian Far East inferred from both nuclear and cytoplasmic markers

Aim The main aim of the present study is to infer the post‐glacial history of Abies species from north‐east Asia and to test the hypotheses that coastal Abies populations suffered less from climatic fluctuations during Pleistocene glacial periods than their more continental counterparts, and that Sakhalin was a major area of introgression. Location Natural ranges of the fir species Abies nephrolepis, Abies sachalinensis and Abies holophylla in the Russian Far East, and of Abies gracilis, which is endemic to the Kamchatka Peninsula. Methods Nineteen populations were sampled for allozyme analysis. Seventeen of these populations were also screened for variation at two paternally inherited chloroplast DNA microsatellite loci (cpSSR) and variation at one maternally inherited mitochondrial marker (nad4‐3/4). Finally a subset of 11 populations was analysed with amplified fragment length polymorphism (AFLP). Comparisons were made with already available Abies sibirica data. For all sets of markers, we estimated genetic diversity and differentiation using an analysis of molecular variance (AMOVA). Population clustering was assessed with a Bayesian approach implemented in structure v.2.3. Results Among the three major species, A. sibirica, A. nephrolepis and A. sachalinensis, A. sachalinensis demonstrated the highest cytoplasmic and nuclear diversity and the most continental species, A. sibirica, the lowest. Both nuclear and mitochondrial DNA markers revealed the presence of a transitional zone on Sakhalin Island between A. nephrolepis and A. sachalinensis of south Sakhalin. The structure analysis delivered very clear results confirming the admixed origin of A. sachalinensis, with a genetic contribution from A. nephrolepis. No variation in cytoplasmic markers was found in A. gracilis, suggesting the occurrence of a recent bottleneck. Main conclusions There is a clear reduction of genetic diversity in Abies species from the Pacific coast into the continent. The higher diversity in A. sachalinensis could have two causes: a larger effective population size in the islands due to relatively stable climatic conditions and consequently less pronounced demographic fluctuations in population size and/or hybridization with continental and Japanese populations. Sakhalin Island is a major transitional zone for conifer species. Finally, the fir from Kamchatka, A. gracilis, should be regarded as a separate species closely related to the A. nephrolepis–A. sachalinensis complex.     

Daphnia size structure,vertical migration,and phosphorus redistribution

The timing and magnitude of diel migration in two daphnid assemblages were determined from a series of vertical profiles of daphnid size distribution. Animals were collected concurrently for gut fullness determination. Only large daphnids (> 1.4 mm) migrated, but these animals could account for substantial vertical and diel differences in phosphorus excretion rate. Gut fullness measurements and time courses of diel vertical migration suggested that large Daphnia can cause a net downward flux of phosphorus during summer in thermally stratified lakes.     

Successful pregnancy in a woman with congenital factor XIII deficiency treated with substitutive therapy. Report of a second case

A syndrome of marked fetal wastage is associated with congenital factor XIII deficiency in adult women. A previously unreported case of a woman with factor XIII deficiency is described, in which substitutive treatment with normal plasma or placental factor XIII concentrate permitted two normal pregnancies. Factor XIII activity was maintained above 1-2% with intermittent infusion of 300 ml to 450 ml of plasma every 14 days or of 500 units of concentrate every 21 days. This case confirms the only other case so far reported in which factor XIII substitutive therapy was able to permit a normal pregnancy in a woman with factor XIII deficiency and seems to suggest factor XIII to be involved in the process of annidation.     

Modulation of asialoglycoprotein binding activity in livers of pregnant or estrogen-treated rats

This report deals with the modulation of activity and expression of the hepatic asialoglycoprotein receptor, in pregnant or diethylstilbestrol-treated rats.The results show a two-fold increase in the total cell associated binding activity, both in pregnant and in estrogen-treated animals, with respect to normal values. On the contrary the surface expression was shown to be strongly enhanced only in the liver of pregnant rat. Therefore the modulation shown by this receptor system in pregnancy seems to be only partially estrogen-dependent.     

1988 Gordon Conference on Theoretical Biology and Biomathematics Tilton Academy, Tilton, New Hampshire, U.S.A., 13–17 June 1988

Announcement

1988 Gordon Conference on Theoretical Biology and Biomathematics Tilton Academy, Tilton, New Hampshire, U.S.A., 13–17 June 1988     

Minor components in food plants--Note I. Flavonol glycosides from Ullucus tuberosus.

This work deals with the isolation and characterization in Ullucus tuberosus of flavonoids, a class of natural products influencing potentially the taste and nutritional value of the plant food. The three flavonoids, rutin, narcissin and kaempferol 3-O-(2",6"-di-O-alpha-L-rhamnopyranosil)-beta-D-glucopyranoside, isolated, are devoid of taste, but appear to possess health promoting effects.     

Ultrastructural analysis of asialoglycoprotein receptor mediated endocytosis in cultured newborn hepatocytes

We examined the receptor-mediated endocytosis of asialoglycoproteins in thick sections of cultured hepatocytes of newborn rats by high voltage electron microscope. The organelles involved in endocytosis are revealed ultrastructurally using colloidal gold particles coupled to lactosylated bovine serum albumin. Keeping the cells at 4 degrees C the marker binds to the cell surface showing microvilli, and is not internalized. Increasing the temperature to 37 degrees C, we observed that within 5-15 min. the marker enters the intracellular endocytic organelles close to the cell surface. After 60 min. the marker is found in the larger and deeper endocytic organelles and in large lisosome-like vesicles. We find that the process of endocytosis in newborn cultured hepatocytes is similar to that found in cultured cells of adult rats, but the process of internalization is slower.     

Characterization of a new hybrid mink-mouse clone panel: chromosomal and regional assignments of the GLO,ACY, NP,CKBB, ADH2, and ME1 loci in mink (Mustela vison)

To expand the mink map, we established a new panel consisting of 23 mink-mouse clones. On the basis of statistical criteria (Wijnen et al. 1977; Burgerhout 1978), we developed a computer program for choice of clones of the panel. Assignments of the following mink genes were achieved with the use of the hybrid panel: glyoxalase (GLO), Chromosome (Chr) 1; acetyl acylase (ACY), Chr 5; creatine phosphokinase B (CKBB), Chr 10; alcohol dehydrogenase-2 (subunit B) (ADH2), Chr 8. Using a series of clones carrying rearrangements involving mink Chr 1 and 8, we assigned the gene for ME1 to the short arm of Chr 1 and that for ADH2 to Chr 8, in the region 8p12-p24. Mapping results confirm the ones we previously obtained with a mink-Chinese hamster panel. However, by means of an improved electrophoretic technique, we revised the localization of the gene for purine nucleoside phosphorylase (NP), which has been thought to be on mink Chr 2. It is reassigned to mink Chr 10.     

The Mr 17500 region of the A chain of urokinase is required for interaction with a specific receptor in A431 cells

We have found the existence of specific receptors for the plasminogen activator, urokinase, in A431 human epidermoid carcinoma cells, cultures in plasminogen-free conditions. Two subsets of receptors have been recognized on the basis of 125I-labelled urokinase binding analysis: about 1 X 10(3) high-affinity (Kd = 5.0 X 10(-11) M) and 1 X 10(5) low-affinity (Kd = 9 X 10(-9) M) receptors per cell. The electron microscopic observation of a urokinase: ferritin conjugate has shown single and clustered receptors at the cell surface. Down-regulation of the receptors (T1/2 = 3.77 h) follows the binding of urokinase. The binding does not involve an intact catalytic site and is inhibited by a monoclonal antibody against the Mr 17500 proteolytic fragment of the A chain of urokinase.