[Changes of Serum Gonadal Hormones Levels During Musk-secreting Period and Estrus of Moschus berezovskii].

OBJECTIVE: To detect concentrations of serum gonadal hormones (testosterone, estradiol and progesterone) in musk-secreting period and estrus of Moschus berezovskii, and to study the association of serum gonadal hormones concentrations and musk-secreting. METHODS: The concentrations of serum gonadal hormones were detected with magnetic particle separation ELISA. RESULTS: During musk-secreting period, concentration changes of three serum gonadal hormones showed clear regularity, three crests occurred synchronously. Before musk-secreting period, testosterone, estradiol and progesterone concentrations were at its lower level, in prime musk-secreting period, they increased rapidly to respective highest peak; at later musk-secreting period, they quickly dropped to close to its previous levels before musk-secreting period. During estrus, serum testosterone concentration increased to lower peaks than that at later musk-secreting period. Estradiol remained at a low level and progesterone level was closed to zero. Serum testosterone concentrations in prime musk-secreting period were 114.4 ~ 190.5 times of estrus. During musk-secreting period, there were significant positive correlation among three serum gonadal hormone levels, a positive correlation between musk yield and serum testosterone levels, and negative correlation of musk yield with serum estradiol and progesterone levels as well as musk deer ages. CONCLUSION: Serum testosterone concentrations in prime musk-secreting period increase to the highest levels,which can provide reference in musk secretion induced by artificial means.

Transgenic tobacco expressing Zephyranthes grandiflora agglutinin confers enhanced resistance to aphids.

Plant lectins have been reported as transgenic resistance factors against a variety of insect pests. Herein, homologous analysis demonstrated that Zephyranthes grandiflora agglutinin (ZGA) exhibited high similarity with other monocot mannose-binding lectins (MBLs). Phylogenetic analysis revealed that it had taxonomical relationships with insecticidal MBLs. Subsequently, a plasmid expression vector pBI121 containing zga gene (pBIZGA) was constructed using the zga sequence, under the control of CaMV35S promoter and nos terminator. pBIZGA was then integrated into the genome of Nicotiana tabacum L. Polymerase chain reaction and Southern blot analysis demonstrated that this zga gene was integrated into the plant genome. Western blotting and agglutinating activity analysis also showed that transgenic tobacco plants expressed different levels of ZGA. Carbohydrate inhibition analysis indicated that recombinant ZGA and the native shared the same carbohydrate-binding specificity. Moreover, genetic analysis confirmed Mendelian segregation (3:1) of the transgenic in T1 progenies. In planta bioassays on T0 plants and their progenies indicated that expressed ZGA had an effect on reducing the survivability and fecundity of tobacco aphids (Myzus nicotianae). These findings demonstrate that the novel zga gene of ZGA can be expressed in crop plants susceptible to various sap-sucking insects.