2005, Vol.18, No.1

Anatomy & Biological Anthropology 2023 KCI Impact Factor : 0.33

pISSN : 2671-5651 / eISSN : 2671-566X
https://journal.kci.go.kr/aba

Sonic hedgehog (Shh) has been known as an essential morphogen for the generation of motor neuron in developing spinal cord. However, motor neuron can be generated in Shh-/-; Gli3-/- or Gli2-/-; Gli3-/- mutants although these mutants don’t have Shh signaling. To find out the compensatory mechanism for the generation of motor neuron in Shh-/-; Gli3-/- mutant, we studied bone morphogenetic protein (BMP) antagonists including follistatin, flik and noggin, and retinoic acid signaling in this mutant. To study expressions of BMP antagonists, we performed in situ hybridization. To examine an activity of retinoic acid, we measured β-galactosidase activity in retinoic acid response element (RARE) transgenic mouse. The expression of follistatin was reduced at both levels of forelimb and hindlimb in Shh-/- mutant compared to wild type embryo. It was restored at the level of forelimb but reduced at the level of hindlimb in Shh-/-; Gli3-/- mutant compared to wild type. The expression of flik was similar with wild type embryo at both levels of forelimb and hindlimb in Shh-/- mutant. The expression of flik was similar with wild type embryo at the level of forelimb however reduced in hindlimb level in Shh-/-; Gli3-/- mutant. The expression of noggin, a BMP antagonist, was increased in Shh-/- mutant. Activity of retinoic acid signaling was not affected in Shh-/- or Shh-/-; Gli3-/- mutants. From these results, we conclude that retinoic acid but not follistatin and flik, may be involved in the generation of motor neuron in Shh-/-; Gli3-/- mutant.

There are many modifications of eye shape and structure among fish, the general plan is similar throughout. This study was performed to comparative investigation for the lens shape and the interlocking pattern of lens fiber in genus Zacco (Z. temmincki and Z. platypus) and Pseudogobio (P. esocinus). The equatorial and axis diameter of lens for the classification of lens shape were measured by micrometer. And the interlocking patterns of lens fibers were observed by scanning electron microscopy (SEM). The lens shapes of Z. platypus and Z. temmincki were spherical (axis /equqtorial diameter = 1), but the lens shape of P. esocinus was subspherical type (axis / equqtorial diameter = 0.87). The interlocking patterns of lens fibers showed that Z. temmincki have an “anchor and socket” connection, Z. platypus have a “ball and socket” connection, and P. esocinus have a “rod and socket” connection. The results of this study may be utilized in the taxonomic keys for the classification of fish.