The application of ethanol-extracted Gloriosa superba for metaphase chromosome preparation in mosquitos.

The application of ethanol-extracted Gloriosa superba for metaphase chromosome preparation in adult and 4th larva Aedes aegypti revealed that 0.5-8% ethanol-extracted Gl. superba solution could be used instead of 1% colchicine in Hanks' balanced salt solution. For adult mosquitos, the metaphase rates and average number of metaphase chromosomes per positive mosquito after intrathoracic inoculation with 1-2% ethanol-extracted Gl. superba solution were 100% and 11.8 (2-16) -12.6 (3-28) in females, and 80-90% and 16.5 (1-52) - 29.89 (1-72) in males, whereas the inoculation with 1% colchicine solution yielded 80% and 50% metaphase rates, and 18.25 (1-40) and 16.5 (2-53) average number of metaphase chromosomes per positive mosquito in females and males, respectively. For 4th stage larvae, the metaphase rates and average number of metaphase chromosomes per positive mosquito after incubation with 0.5-8% ethanol-extracted Gl. superba solution were 90-100% and 14.42 (1-65) - 64 (19-137), while incubation with 1% colchicine solution yield 100% metaphase rate and 10.9 (7-15) average number of metaphase chromosomes per positive mosquito.

Autogenous Aedes togoi sub-colony (Chanthaburi, Thailand strain), an efficient laboratory vector in study of filariasis.

Comparative filarial susceptibility and biology between stock colony and selectively autogenous Aedes. togoi sub-colony were carried out to determine the laboratorial vector-capacity and viability of autogenous sub-colony. The results of susceptibility revealed that the selectively autogenous Ae. togoi sub-colony yielded higher susceptibility than the stock colony, ie Dirofilaria immitis: susceptibility rates=80.00% [Exp1(F8)] and 76.19% [Exp2(F17)] (autogenous sub-colony), 53.33% (Exp1) and 71.43% (Exp2) (stock colony); Brugia malayi: susceptibility rates=83.33% [Exp1(F17)] and 84.38% [Exp2(F19)] (autogenous sub-colony), 81.25% (Exp1) and 75.00% (Exp2) (stock colony), but not at the level of statistically significant differences except the Exp1 of D. immitis, which was significant difference. In addition, the average No. L3 per infected mosquito in the selective autogenous sub-colony (D. immitis: Exp1=3.37, Exp2=3.19; B. mallayi: Exp1=8.80, Exp2=3.37) was also higher than in stock colony (D. immitis: Exp1=2.44, Exp2=2.73; B. malayi: Exp1=7.85, Exp2=3.02), but not at the level of statistically significant difference. The results of comparisons on some biological aspects demonstrated that most of the cases they have similar biology except the average egg deposition per gravid female of stock colony (130.17+/-43.33) was significantly more than selectively autogenous sub-colony(F9) (94.33+/-13.69), egg length x width 575.62+/-18.06 microm x 186.15+/-9.35 microm of stock colony was significantly larger than selectively autogenous sub-colony(F9) 560.49+/-18.96 microm x 177.99+/-8.40 microm, and mean longevity of adult female of stock colony [41.60(6-61)] was significantly longer than selectively autogenous sub-colony(F9) [35.00(5-39)]. The selectively autogenous sub-colony was established and twenty-two successive generations have been colonized.

Comparative morphometry, morphology of egg and adult surface topography under light and scanning electron microscopies, and metaphase karyotype among three size-races of Fasciola gigantica in Thailand.

Comparative morphometry of eggs and adults under light microscope, and morphology of adults under scanning electron microscope (SEM) were undertaken in the three size-races (< 25 mm, 25-35 mm, > 35 mm) of Fasciola gigantica (Thailand strain). Morphometric examination revealed intraspecific variation with respects to the dimensions of eggs and adults, whereas surface topography of the three size-race adults under SEM was morphologically similar. The observations on mitotic metaphase chromosomes of spermatogonial cells from testes of the three size-races revealed 2n=20 (diploid type), and no karyotypic difference was observed among them. The meiotic metaphase chromosome was 10 bivalents in primary spermatocyte in diplotene to diakinesis, and many mature spermatozoa were seen in the testicular preparations.