Functional Study Of LOXL3 Gene In The Palate And Spine Development Of Mice

Lysyl oxidase is an extracellular copper enzyme that initiate the formation of the lysine crosslinks in collagens and elastin.The crosslinks transform the soluble monomer in the collagens and elastin into the insoluble fiber in the extracellular matrix.Then human found lysyl oxidase-like 1(LOXL1),lysyl oxidase-like 2(LOXL2),lysyl oxidase-like 3(LOXL3)and lysyl oxidase-like 4(LOXL4).Those five members consist of the lysyl oxidase family.So far,there are many researches on the functions of LOX and LOXL1.However,the functions of the other members is not clear.So our laboratory have taken gene knock-out technology to design and produce Loxl3 floxed mice.The EIIa-Cre transgenic mice have been reported to induce Cre-mediated recombination in almost all tissues.The Loxl3 floxed mice mated with Ella-Cre transgenic mice.Then we can obtain the mouse of inactivating Loxl3 in the whole body.It is possible for us to study the effect of Loxl3 gene deletion on the embryonic development.The mouse of inactivating LOXL3 in the whole body died immediately after delivery.The newborn Loxl3-/-pups had severe cleft palate and spinal deformity.We detected the changes of embryonic palatal development in mice.From the embryonic day 14.5,compared with the wild type mice,the palatal shelves of Loxl3-/-mouse failed to elevate.At embryonic day 16.5,although the palatal shelves of Loxl3-/-mouse elevate,the opposing palatal shelves didn’t further contact and fuse.We also found that from the embryonic day 14.5,the cartilage primordial of thoracic vertebrae were malformed in Loxl3-/-mouse.It leaded to spinal deformity in Loxl3-/-mouse.The spinal deformity became more serious at the embryonic day 16.5.The amount of collagen type Ⅰ in the palate and spinal columns was abundant.We found that the amount of collagen type Ⅰ in the Loxl3-/-mouse had decreased significantly.At the same time,the Hydroxyproline test also indirect estimated the amount of collagen in the the Loxl3-/-mouse was lower than the wild type mice.We speculated that the deletion of Loxl3 inhibited the formation of collagen in the normal form.Therefore,we assumed that Loxl3 paly an important part in the development of palate and spine in the mice.