Regulation of the retinal determination gene dachshund in the embryonic head and developing eye of Drosophila

Abstract

The retinal determination gene dachshund is distantly related to the family of Ski/Sno proto-oncogenes and influences the development of a wide range of tissues including the embryonic head, optic lobes, brain, central nervous system as well as the post-embryonic leg, wing, genital and eye-antennal discs. We were interested in the regulatory mechanisms that control the dynamic expression pattern of dachshund and in this report we set out to ascertain how the transcription of dachshund is modulated in the embryonic head and developing eye-antennal imaginal disc. We demonstrate that the TGFbeta signaling cascade, the transcription factor zerknullt and several other patterning genes prevent dachshund from being expressed inappropriately within the embryonic head. Additionally, we show that several members of the eye specification cascade influence the transcription of dachshund during normal and ectopic eye development. Our results suggest that dachshund is regulated by a complex combinatorial code of transcription factors and signaling pathways. Unraveling this code may lead to an understanding of how dachshund regulates the development of many diverse tissue types including the eye.

Differential recruitment of limb patterning genes during development and diversification of beetle horns

“…Also, larval Otdac RNAi resulted in smaller compound eyes with rough ommatidial surfaces, including ommatidial misarrangements and partial fusion of ommatidia, phenotypes similar to those observed in Drosophila dac mutants (Fig. 3A) (37). These phenotypes were observed in 81% of pupae (n ϭ 25/31) and 89% (n ϭ 16/18) of adults generated.…”

The Eyes Absent Family of Phosphotyrosine Phosphatases: Properties and Roles in Developmental Regulation of Transcription

“…Genetic epistasis analyses position dac as the most downstream among the known components of the RDGN (Figure 1) (9,10). Retinal tissue with mutations in ey, so, or eya has markedly reduced levels of dac expression (9,10,42,63), suggesting that Ey, So, and Eya are primary regulators of dac expression; however, persistence of a low level of dac expression implies additional factors may modulate www.annualreviews.org • Eya Phosphotyrosine PhosphatasesBMP: Bone Morphogenetic Protein its expression. Identification and characterization of two eye-specific enhancer elements within the dac genomic locus support this idea (64).…”

Effect of Two Natural Antioxidant Intervention on Plasma Vitamin C, E, and β-Carotene Concentrations of Apparently Healthy Adults in Nasarawa State University, Keffi, Nigeria

“…Some studies indicate that Vitamin C increases circulating immunoglobulin (Ig) levels in humans [17]. Vitamin C provide important protection for plasma lipid and lipid membranes and can neutralize phagocyte-derived oxidants released extracellular, thereby preventing oxidant mediated tissue damage [10]. This study showed that Vitamin C concentration showed no significant difference between the male and female levels.…”

“…Micronutrients deficiency is common in ageing, pregnancy and ill health [14]. These deficiencies may contribute to an increased risk of parasitic infection, and oxidative stress which affect the production of blood cells and haemoglobin and the entire immune level [10]. The study showed that there is synergism between α-tocopherol, β-carotene and ascorbic acid.…”

“…Antioxidant vitamins (Ascorbic acid and tocopherol) and carotenoids have been suggested to play important role in cellular immunity and cardiovascular diseases [6] [7] [8]. Vitamin C is found in high concentration in white blood cells and is rapidly utilized during infection; reduced plasma concentrations are often associated with reduced immune function [9] Vitamin C provide important protection for plasma lipid and lipid membranes and can neutralize phagocyte-derived oxidants released extracellular, thereby preventing oxidant mediated tissue damage [10]. Vitamin E is the most effective chain-breaking, lipid soluble antioxidant present in cell membranes, thus play a role in limiting lipid peroxidation as well as in immune cell function [11].…”