Molecular systematic studies on mandarina silkworm (Bombyx mandarina M.) in 11 regions in China and 25 representative strains of domestic silkworm (Bombyx mori L.) were conducted using molecular biology techniques. Re...Molecular systematic studies on mandarina silkworm (Bombyx mandarina M.) in 11 regions in China and 25 representative strains of domestic silkworm (Bombyx mori L.) were conducted using molecular biology techniques. Results obtained from the analysis of DNA polymorphism and clustering of all the silkworm samples provide new evidence for the view that the domestic silkworm originated from the Chinese mandarina silkworm. On the basis of literature reviewing, a new hypothesis on the origin of the domestic silkworm was put forward. It was thought that the domestic silkworm was most probably domesticated from the Chinese mandarina silkworm of different ecotypes including monovoltinism, bivoltinism and multivoltinism; and that the domestic silkworm had the genetic background of monovoltinism, bivoltinism and multivoltinism at the very beginning of the domestication. The current strains of the domestic silkworm of different voltinism are the evolutionary results of thousands of years of rearing and artificial selections.展开更多
Diapause eggs of Bombyx mandarina Moore from Wujiang, Jiangsu Province, China, were used to study the artificial hatching of B. mandarina Moore. The results showed that the highest hatchability was obtained by instant...Diapause eggs of Bombyx mandarina Moore from Wujiang, Jiangsu Province, China, were used to study the artificial hatching of B. mandarina Moore. The results showed that the highest hatchability was obtained by instant treatment with hydrochloric acid （HC1, specific gravity 1.065-1.075） for 5 rain under 46℃. After the B. mandarina eggs were cold stored at 5℃ for 40 days, the highest hatchability was obtained by treatment with HC1 （specific gravity 1.092） for 6 minutes under 47.8℃. For the B. mandarina eggs that were stored at 25℃ for 28 d and then cold-stored at 5℃ for 0-100 days, the highest hatchability was obtained by treatment with HCI （specific gravity 1.092） for 6 rain at 47.8℃. The longer the cold storage period, the higher was the hatchability. Acid treatment on diapause eggs of B. mandarina for 6 rains at 47.8℃ with hydrochloric acid （specific gravity 1.092） before hatching in spring could obviously shorten the hatching stage and increase the hatchability.展开更多
The cDNA encoding an antiviral protein SP-2 against BmNPV was cloned from the midgut of Chinese wild silkworm, Bombyx mandarina Moore (GenBank access AY945210) based on the available informa- tion of the domesticated ...The cDNA encoding an antiviral protein SP-2 against BmNPV was cloned from the midgut of Chinese wild silkworm, Bombyx mandarina Moore (GenBank access AY945210) based on the available informa- tion of the domesticated silkworm. Its cDNA was 855 bp encoding 284 amino acids with predicted mo- lecular weight of 29.6 kDa. Its full length in genomics was 1376 bp, including 5 exons and 4 introns. The expression analysis indicated that it was only expressed in midgut, and its expression level was higher during feeding stage of larval instars while very lower during the moltism and mature stages. The de- duced amino acid sequence of this protein showed eight-amino-acid variation compared with the counterpart of domesticated silkworm. Its antiviral activity was assayed through in vitro test. The re- sults indicated that it showed strong bioactivity against BmNPV, and its activity was 1.6 fold higher that the counterpart of domesticated silkworm.展开更多
基金supported by the National Natural Science Foundation of China(No.39870603)the Special Funding Program of the Ministry of Education for Ph.D.Degree Awarding Units.
文摘Molecular systematic studies on mandarina silkworm (Bombyx mandarina M.) in 11 regions in China and 25 representative strains of domestic silkworm (Bombyx mori L.) were conducted using molecular biology techniques. Results obtained from the analysis of DNA polymorphism and clustering of all the silkworm samples provide new evidence for the view that the domestic silkworm originated from the Chinese mandarina silkworm. On the basis of literature reviewing, a new hypothesis on the origin of the domestic silkworm was put forward. It was thought that the domestic silkworm was most probably domesticated from the Chinese mandarina silkworm of different ecotypes including monovoltinism, bivoltinism and multivoltinism; and that the domestic silkworm had the genetic background of monovoltinism, bivoltinism and multivoltinism at the very beginning of the domestication. The current strains of the domestic silkworm of different voltinism are the evolutionary results of thousands of years of rearing and artificial selections.
基金supported by the National Natural Science Foundation of China(30471309)the National Basic Research Program of China(2005CB121005).
文摘Diapause eggs of Bombyx mandarina Moore from Wujiang, Jiangsu Province, China, were used to study the artificial hatching of B. mandarina Moore. The results showed that the highest hatchability was obtained by instant treatment with hydrochloric acid （HC1, specific gravity 1.065-1.075） for 5 rain under 46℃. After the B. mandarina eggs were cold stored at 5℃ for 40 days, the highest hatchability was obtained by treatment with HC1 （specific gravity 1.092） for 6 minutes under 47.8℃. For the B. mandarina eggs that were stored at 25℃ for 28 d and then cold-stored at 5℃ for 0-100 days, the highest hatchability was obtained by treatment with HCI （specific gravity 1.092） for 6 rain at 47.8℃. The longer the cold storage period, the higher was the hatchability. Acid treatment on diapause eggs of B. mandarina for 6 rains at 47.8℃ with hydrochloric acid （specific gravity 1.092） before hatching in spring could obviously shorten the hatching stage and increase the hatchability.
基金the National High-tech Research Program (863Program) of China(GrantNo.2007AA10Z159)the State Key Basic Research Program (973Program) of China (GrantNo.2005CB121003)the New-Century Training Program Foundation for the Talents of the Ministry of Education of China (GrantNo.NCET-06-0524)
文摘The cDNA encoding an antiviral protein SP-2 against BmNPV was cloned from the midgut of Chinese wild silkworm, Bombyx mandarina Moore (GenBank access AY945210) based on the available informa- tion of the domesticated silkworm. Its cDNA was 855 bp encoding 284 amino acids with predicted mo- lecular weight of 29.6 kDa. Its full length in genomics was 1376 bp, including 5 exons and 4 introns. The expression analysis indicated that it was only expressed in midgut, and its expression level was higher during feeding stage of larval instars while very lower during the moltism and mature stages. The de- duced amino acid sequence of this protein showed eight-amino-acid variation compared with the counterpart of domesticated silkworm. Its antiviral activity was assayed through in vitro test. The re- sults indicated that it showed strong bioactivity against BmNPV, and its activity was 1.6 fold higher that the counterpart of domesticated silkworm.
