Genetic composition of exotic and native teak (<Emphasis Type="Italic">Tectona</Emphasis><Emphasis Type="Italic">grandis</Emphasis>) in Myanmar as revealed by cpSNP and nrSSR markers

With the rapid fragmentation of tropical forests harboring valuable tree species, conservation of natural genetic resources is an important issue. In Myanmar, teak plantations have been established by Myanmar government since the 1700 s using local Myanmar teak. Commercial plantations have recently been established by the private sector using both exotic and Myanmar teak without consideration of their genetic make-up. If the genetic composition of commercial teak plantations is severely different from that of Myanmar teak, introgression of non-indigenous genes could damage the remaining natural populations. We investigated genetic compositions of commercial plantations using both exotic and Myanmar teak seeds with 10 nuclear simple sequence repeat and three chloroplast single nucleotide polymorphism markers. We then compared the genetic compositions of these populations with those of neighboring native teak forests. The genetic diversity and composition of one exotic plantation using Costa Rican seeds was similar to those of native populations. However, the diversity of the other three exotic plantations was low and their composition was markedly different from those of native populations. Our results suggest that exotic gene flow would cause serious genetic disturbance. Commercial plantations using Myanmar seeds were characterized by relatively high genetic diversity and by many genetic components. These results suggest that these plantations may be established using various seed sources in Myanmar. Given that native teak in Myanmar is geographically structured, native gene pools will be homogenized by gene flow from these commercial plantations. Seed transfer guidelines based on genetic information should be considered in future.     

A polymorphism detected in a variable number of tandem repeats (VNTR) of the seminal vesicle secretion (SVS) IV gene in inbred rats

The second intron of the rat SVS IV gene contains a tandem repeat region of 20-bp sequences. This region was amplified using the polymerase chain reaction to detect variations. Three alleles, characterized by amplified fragments of 750, 490, and 390 bp, respectively, were found in 24 strains examined. This variation segregated in F₁ and backcross progeny in an autosomal codominant manner. We tentatively designated this locusSvs-4. Analysis of linkages between theSvs-4 locus and other loci revealed that it was closely linked to theSvp-1 (<2.9%) and the a (10.0±6.7%) loci, which belong to rat linkage group IV. TheSvp-1 andSvs-4 loci, however, were differently distributed among the inbred rat strains.This work was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan.     

Possible role of a 36 kDa protein induced by respiratory inhibitors in cyanide-resistant respiration in Hansenula anomala

The antimycin A or cyanide-dependent appearance of a 36 kDa protein in the particulate fraction was observed in L-[35S]methionine pulse-labeling experiments on cells of Hansenula anomala, in which cyanide-resistant respiration was induced. The combined addition of cycloheximide or anaerobiosis, which block the induction of cyanide-resistant respiration, repressed the synthesis of this protein. These results suggest the involvement of the particulate 36 kDa protein in cyanide-resistant respiration.     

Nestmate discrimination in the queenless ponerine ant Diacamma sp. from Japan

We examined the nestmate discrimination ability of Diacamma sp., an ant that reproduces by colony budding. We also tested for a relationship between internest distance and hostility. Hostility toward non‐nestmates was significantly stronger than that toward nestmates, suggesting that Diacamma sp. discriminates between nestmates and non‐nestmates. There was no significant correlation between internest hostility and internest distance, which indicates the absence of a “dear enemy” phenomenon in this species.     

Studies on Cycasin,a New Toxic Glycoside,of Cycas revoluta Thunb

The enzymatic hydrolysis of cycasin with cycad-emulsin, prepared from the seeds of Cycas revoluta, is described. As the complete degradation products we obtained about one mole each of formaldehyde, nitrogen gas, and methanol per mole of cycasin, in addition to glucose, the sugar component. These products are the same as those found in the acid hydrolysis of cycasin which has been reported previously. Therefore, it is concluded that the aglycone of cycasin can not be liberated intact as a single component, but decomposes into those smaller molecules as above even by means of the enzymatic hydrolysis.     

The bumblebee Bombus ardens ardens (Hymenoptera: Apidae) visits white clover in orchards before Oriental persimmon blooms

Flowers on the ground of orchards can provide substantial resources for wild pollinators of orchard trees. Few studies, however, have examined the relative importance of groundcover flowers to orchard pollination by analyzing pollen on the body surface of pollinators. Oriental persimmon trees bloom within the longer blooming period of white clover, which is occasionally found as a flowering plant on the ground of persimmon orchards in Japan. The present study compared the insect species assemblage collected on persimmon flowers with that on clover. Before persimmon bloomed, Bombus ardens ardens and Apis cerana japonica were the major visitors of clover flowers. Once persimmon bloomed, the former was the most abundant bee that visited persimmon flowers over the flowering period. Apis mellifera was captured only on clover flowers. We found numerous clover pollen grains on the body surface of bumblebees captured on persimmon flowers, but far fewer persimmon pollen grains on bees that visited clover. These findings show that B. ardens ardens utilized the clover flowers under the orchards before persimmon bloomed.     

A green tea extract high in catechins reduces body fat and cardiovascular risks in humans

Objective: The body fat reducing effect and reduction of risks for cardiovascular disease by a green tea extract (GTE) high in catechins was investigated in humans with typical lifestyles. Research Methods and Procedures: Japanese women and men with visceral fat‐type obesity were recruited for the trial. After a 2‐week diet run‐in period, a 12‐week double‐blind parallel multicenter trial was performed, in which the subjects ingested green tea containing 583 mg of catechins (catechin group) or 96 mg of catechins (control group) per day. Randomization was stratified by gender and body mass index at each medical institution. The subjects were instructed to maintain their usual dietary intake and normal physical activity. Results: Data were analyzed using per‐protocol samples of 240 subjects (catechin group; n = 123, control group; n = 117). Decreases in body weight, body mass index, body fat ratio, body fat mass, waist circumference, hip circumference, visceral fat area, and subcutaneous fat area were found to be greater in the catechin group than in the control group. A greater decrease in systolic blood pressure (SBP) was found in the catechin group compared with the control group for subjects whose initial SBP was 130 mm Hg or higher. Low‐density lipoprotein (LDL) cholesterol was also decreased to a greater extent in the catechin group. No adverse effect was found. Discussion: The continuous ingestion of a GTE high in catechins led to a reduction in body fat, SBP, and LDL cholesterol, suggesting that the ingestion of such an extract contributes to a decrease in obesity and cardiovascular disease risks.