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LIM homeodomain proteins Islet‐1 and Lim‐3 expressions in the developing pineal gland of chick embryo by immunohistochemistry
Author(s) -
Zhang JinHua,
Liu JiaLi,
Wu YingJie,
Cui Sheng
Publication year - 2006
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.2006.00363.x
Subject(s) - islet , biology , pineal gland , immunohistochemistry , endocrinology , embryo , medicine , enteroendocrine cell , pinealocyte , homeobox , microbiology and biotechnology , melatonin , endocrine system , hormone , immunology , gene expression , biochemistry , insulin , gene
LIM homeodomain proteins Islet‐1 and Lim‐3 expression and their role in nervous tissue and endocrine glands have been reported; however, nothing is known concerning Islet‐1 and Lim‐3 expression in the developing pineal gland of the chick embryo. The aim of the present study was to determine the ontogeny of Islet‐1 and Lim‐3 expression in the developing pineal gland of chick embryo using immunohistochemistry. The results showed that Islet‐1 and Lim‐3 immunopositive cells were first detected in the pineal evagination of chick embryos at day 4 (E4) and E4.5 of incubation, respectively. In the later developing stages, both Islet‐1 and Lim‐3 immunopositive cells were consistently detected in the follicular and parafollicular pinealocytes throughout the pineal gland. The relative percentage of Islet‐1 immunopositive (Islet‐1 + ) cells relative to the total cells was about 6% at E4.5, and then kept increasing ( P < 0.05) and reached about 40% by E12.5; this was followed by no obvious changes until the chicks were newly hatched. The change in Lim‐3 immunopositive (Lim‐3 + ) cell number was parallel to that of Islet‐1, although Lim‐3 + cell were significantly fewer than Islet‐1 + cell numbers from E4.5 to E8.5 ( P < 0.05). Dual immunohistochemical staining results showed that almost all the Lim‐3 + cells expressed Islet‐1 at every stage examined, and about 90% of Islet‐1 + cells were proliferating cell nuclear antigen negative. These results suggest that both Islet‐1 and Lim‐3 may be involved in regulating the development and functional maturation of the pineal gland, although further studies are required in elucidating the functional roles of Islet‐1 and Lim‐3 and the related mechanisms.