The role of Dby mRNA in early development of male mouse zygotes

Ejaculated mammalian spermatozoa contain a complex yet specific population of mRNA. However, the possible roles that mRNA has in early zygotic and embryonic development remain unclear. We found that Dby mRNA is selectively retained in capacitated mouse spermatozoa, and is transferred into the oocyte during fertilization by reverse transcription-polymerase chain reaction even though no DBY protein expression is detected. The cellular location ofDby mRNA is seen in the post-acrosome region, and it comprises nearly half of the mouse spermatozoa in in situ hybridization. In contrast, transcripts of the control gene, Smcy, are not detected in capacitated mouse spermatozoa, although the H-Y antigen encoded by Smcy is expressed on the surface of the spermatozoa. In our microinjection experiment, the zygotic development rate of the as-Dby male pronucleus injection group was significantly lower than that of the as-Smcy male pronucleus injection group （35.9% vs. 95%, P = 0.001） and the as-Dby female pronucleus injection group （35.9% vs. 93.8%, P = 0.001）. The rate of male-developed zygotes was also lower than that of the as-Smcy male pronucleus injection group （17.4% vs. 57.9%, P = 0.002） and the as-Dby female pronucleus injection group （17.4% vs. 54.1%, P = 0.002）. Thus, we conclude that Dby mRNA is selectively retained in capaci- tated mouse spermatozoa, and it has an important role in the early zygotic development of male mouse zygotes. This might imply that spermatozoa mRNA is involved in early zygotic and embryonic stages of reproduction.

Activation of JNK signaling links lgl mutations to disruption of the cell polarity and epithelial organization in Drosophila imaginal discs

Dear Editor, Identification of Drosophila melanogaster as a model organism for cancer research has facilitated the exploration of human tumor malignancy. In Drosophila, loss- of-function mutations in the neoplastic tumor suppressor genes （nYSGs） lethal（2）giant larvae （lgl）, discs large （dlg） or scribble （scrib） cause a malignant tumor-like phenotype characteristic of disrupted cell polarity and overgrowth in epithelial tissues such as imaginal discs [1 ].

Lethal（2）giant larvae is required in the follicle cells for formation of the initial AP asymmetry and the oocyte polarity during Drosophila oogenesis

The intricately regulated differentiation of the somatic follicle cell lineages into distinct subpopulations with specific functions plays an essential role in Drosophila egg development. At early oogenesis, induction of the stalk cells generates the first anteroposterior （AP） asymmetry in the egg chamber by inducing the posterior localization of the oocyte. Later, the properly specified posterior follicle cells signal to polarize the oocyte along the AP and dorsoventral （DV） axes at mid-oogenesis. Here, we show that lethal（2）giant larvae （lgl）, a Drosophila tumor suppressor gene, is required in the follicle cells for the differentiation of both stalk cells and posterior follicle cells. Loss-of-function mutations in lgl cause oocyte mispositioning in the younger one of the fused chambers, due to lack of the stalk. Removal oflgl function from the posterior follicle cells using the FLP/FRT system results in loss of the oocyte polarity that is elicited by the failure of those posterior cells to differentiate normally. Thus, we provide the first demonstration that lgl is implicated in the formation of the initial AP asymmetry and the patterning of the AP and DV axes in the oocyte by acting in the specification of a subset of somatic follicle cells.

BmApontic is involved in neurodevelopment in the silkworm Bombyx mori

The nervous system of the silkworm is vital for the development of organisms.It achieves and maintains normal life activities by regulating the function of the organs and all kinds of physiological processes in the silkworm.BmApontic(BmApt),as an imports nt bZIP tran scripti on factor,is required for the formatio n of pigme ntation in the silkworm.However,the fun ction of BmApt in the development of the nervous system of the silkworm remains unclear.Here,we showed that amino acid seque nee of BmApt was evoluti on arily con served in its Myb/SANT motif and basic DNA bindi ng domain.BmApt was expressed in the nervous system at the embry onic stage.Knockdow n of Bmapt by RNA interfere nee resulted in abno rmal development of axons.Moreover,the expression of BmnetrinA,BmnetrinB and Bmfrazzled was decreased in the Bmapt knockdown embryos.These results dem on strate that BmApt controls neurodevelopme nt by activati ng the expressi on of Bmnetrin and Bmfrazzled.

凝聚专家的力量提高低收入国家的妇幼保健质量--美国出生缺陷基金会资助的全球妇幼保健协作项目

This short report describes a model for international collaboration on perinatal health that is innovative,highly-productive and challenging. The model,funded by the U.S. March of Dimes Foundation and entitled the 'March of Dimes Global Network for Maternal and Infant Health(GNMIH)' ,allows developing country experts to more easily share their knowledge,experience,skills and materials in ways that can improve women's,maternal,newborn and child health in lower-income countries. This report begins with a brief description of the March of Dimes and its Global Programs which oversees the GNMIH. It then discusses the structure of the GNMIH,with an emphasis on the benefits and challenges of working within the network,and concludes with a brief description of the acti-vities of network members.