Katagiri T, Boorla S, Frendo J L, Hogan B L, Karsenty G
Department of Molecular Genetics, University of Texas M.D. Anderson Cancer Center, Houston, USA.
Dev Genet. 1998;22(4):340-8. doi: 10.1002/(SICI)1520-6408(1998)22:4<340::AID-DVG4>3.0.CO;2-6.
Analysis of the skeletal phenotypes caused by the genetic inactivation of individual Bmps, along with the study of their expression patterns, suggest possible functional redundancy of these molecules. To investigate the effect on skeleton development of the combined absence of some Bmp genes expressed in the same areas, we have intercrossed heterozygous Bmp7 mice with Bmp2 +/-, Bmp4 +/-, or Bmp5 +/- animals. Bmp2/7 and Bmp5/7 double heterozygous animals do not present with any abnormalities. In contrast, Bmp4/7 double heterozygotes develop minor defects in two restricted areas of the skeleton, the rib cage, and the distal part of the limbs. In the ribs, Bmp4 and Bmp7 seem to act in the same pathway to assure proper guidance of mesenchymal condensations of the ribs extending toward the sternum. In the limbs, these molecules appear to play a similar role in controlling digit number, possibly through induction of apoptosis in the interdigital and anterior mesenchyme.
对个别Bmp基因的遗传失活所导致的骨骼表型进行分析，并结合对其表达模式的研究，显示出这些分子可能存在功能冗余。为了研究在同一区域表达的某些Bmp基因共同缺失对骨骼发育的影响，我们将杂合的Bmp7小鼠与Bmp2 +/ -、Bmp4 +/ -或Bmp5 +/-动物进行了杂交。Bmp2/7和Bmp5/7双杂合动物没有出现任何异常。相比之下，Bmp4/7双杂合子在骨骼的两个受限区域，即胸廓和肢体远端，出现了轻微缺陷。在肋骨中，Bmp4和Bmp7似乎在同一路径中发挥作用，以确保向胸骨延伸的肋骨间充质凝聚物得到正确引导。在肢体中，这些分子似乎在控制指（趾）数量方面发挥着类似作用，可能是通过诱导指间和前部间充质中的细胞凋亡来实现的。
