أحمد عبدالله.
02-25-2014, 04:14 PM
بسم الله....
كنت اجول في البحث على رد لاحدى الشبهات فوجدت تناقضا من اوسع ابوابه بين ورقتين... وهو يخص وجود جين bmp4 في منقار الدجاج... فدراسة تؤكد انه هو المسؤول عن شكل المنقار في حين تدعي اخرى ان نقصان هذا الجين هو الذي حرم الدجاج من الاسنان
الدراسة الاولى
Conservation of early odontogenic signalingpathways in Aves
YiPing Chen* Yanding Zhang, Ting-
Xing Jiang Amanda J. Barlow§, Tara R. St. Amand Yueping Hu Shaun Heaney*, Philippa Francis-West§, Cheng-Ming Chuong and Richard Maas*¶
However, the expression of three molecules involved in tooth initiation, Bmp4, Msx1, and Msx2, are absent from the presumptive chick dental
lamina.
وكذلك
FGF8 and BMP4 each can differentially regulate the expression of Msx1 and Msx2 as well as that of the distal-less homeobox genes Dlx1 and Dlx2 in dental mesenchyme, and both Dlx and Msx genes function in dental mesenchymal induction (5, 11, 12).
اما الورقة الثانية
Bmp4 and Morphological Variation of Beaks in Darwin’s Finches
Arhat Abzhanov,1 Meredith Protas,1 B. Rosemary Grant,2 Peter R. Grant,2 Clifford J. Tabin1*
Darwin’s finches are a classic example of species diversification by natural selection. Their impressive variation in beak morphology is associated with the exploitation of a variety of ecological niches, but its developmental basis is unknown. We performed a comparative analysis of expression patterns of various growth factors in species com- prising the genus Geospiza. We found that expression of Bmp4 in the mesenchyme of the upper beaks strongly correlated with deep and broad beak morphology. When misexpressed in chicken embryos, Bmp4 caused morphological transformations par- alleling the beak morphology of the large ground finch G. magnirostris.
وكذلك
In G. difficilis, Bmp4 expression is first seen at low levels in the subectodermal mesenchyme at stage 26 (Fig. 1B). Once the cartilage condensation has occurred at stage 29, Bmp4 continues to be expressed in mesenchymal cells surround- ing the most rostral part of the prenasal car- tila
كنت اجول في البحث على رد لاحدى الشبهات فوجدت تناقضا من اوسع ابوابه بين ورقتين... وهو يخص وجود جين bmp4 في منقار الدجاج... فدراسة تؤكد انه هو المسؤول عن شكل المنقار في حين تدعي اخرى ان نقصان هذا الجين هو الذي حرم الدجاج من الاسنان
الدراسة الاولى
Conservation of early odontogenic signalingpathways in Aves
YiPing Chen* Yanding Zhang, Ting-
Xing Jiang Amanda J. Barlow§, Tara R. St. Amand Yueping Hu Shaun Heaney*, Philippa Francis-West§, Cheng-Ming Chuong and Richard Maas*¶
However, the expression of three molecules involved in tooth initiation, Bmp4, Msx1, and Msx2, are absent from the presumptive chick dental
lamina.
وكذلك
FGF8 and BMP4 each can differentially regulate the expression of Msx1 and Msx2 as well as that of the distal-less homeobox genes Dlx1 and Dlx2 in dental mesenchyme, and both Dlx and Msx genes function in dental mesenchymal induction (5, 11, 12).
اما الورقة الثانية
Bmp4 and Morphological Variation of Beaks in Darwin’s Finches
Arhat Abzhanov,1 Meredith Protas,1 B. Rosemary Grant,2 Peter R. Grant,2 Clifford J. Tabin1*
Darwin’s finches are a classic example of species diversification by natural selection. Their impressive variation in beak morphology is associated with the exploitation of a variety of ecological niches, but its developmental basis is unknown. We performed a comparative analysis of expression patterns of various growth factors in species com- prising the genus Geospiza. We found that expression of Bmp4 in the mesenchyme of the upper beaks strongly correlated with deep and broad beak morphology. When misexpressed in chicken embryos, Bmp4 caused morphological transformations par- alleling the beak morphology of the large ground finch G. magnirostris.
وكذلك
In G. difficilis, Bmp4 expression is first seen at low levels in the subectodermal mesenchyme at stage 26 (Fig. 1B). Once the cartilage condensation has occurred at stage 29, Bmp4 continues to be expressed in mesenchymal cells surround- ing the most rostral part of the prenasal car- tila