Expression of small heat shock protein genes in normal limbs and retinoic acid-induced short limb malformations during mouse embryogenesis

Objective:To study the expression of small heat shock proteins genes (sHsps) in normal forelimbs and forelimb malformations during mouse embryogenesis.Methods: At gestational day (GD) 10,mice of the treatment and the control groups were administered with 80 mg/kg retinoic acid and the same volume of vegetable oil,respectively.The embryonic forelimbs were harvested in GD11-18.The relative abundance of 15 Hsps of all samples was measured by reverse transcript polymerase chain reaction (RT-PCR).Results: In the normal limbs,Hspb4 expressed from GD12,and all other 14 Hsps expressed in GD11-18.Also in the normal limbs,the expressional abundance of Hsp10,Hsp20, Hspb2 and Hspb3 was stable,and that of Hsp22,Hsp30 was increased with the aging of embryos.Hsp25 was highly expressed initially,and then descended and remained at a low level in the normal limbs.The expressional peak of Hspb4 was at GD15 in the normal limbs,and that of Hspb9 was at GD11 and GD14.The expressional abundance of most of the genes in the treatment group was higher than that of the control group in GD11-18.The expression of some genes was obviously different during the development of the normal and the abnormal limbs.For example,the expressional tendency of Hsp25 of the abnormal limbs and the normal limbs was different; the expressional abundance of the normal limbs was higher than that of the abnormal limbs in GD11-12,but lower than that of the abnormal limbs in GD14-18.The expression of Hspb7 started from GD13 in the abnormal limbs,and descended after GD15.The expression of Hspb10 in the abnormal limbs was detected in GD12-16 only.Conclusion: Different Hsps have different expressional characteristics.The expression abundance of most genes in the abnormal limbs is higher than that in the normal limbs.The expressional patterns of some genes in the abnormal limbs are obviously different from those of the normal limbs.