AN ULTRASTRUCTURAL ANALYSIS OF THE ECDYSONELESS (L(3)ECD1TS) RING GLAND DURING THE 3RD LARVAL INSTAR OF DROSOPHILA-MELANOGASTER

被引:14
作者
DAI, JD [1 ]
HENRICH, VC [1 ]
GILBERT, LI [1 ]
机构
[1] UNIV N CAROLINA, DEPT BIOL, CB 3280 COKER HALL, CHAPEL HILL, NC 27599 USA
关键词
PROTHORACIC GLAND; ECDYSTEROID; CORPUS ALLATUM; JUVENILE HORMONE; DROSOPHILA-MELANOGASTER (INSECTA);
D O I
10.1007/BF00340866
中图分类号
Q2 [细胞生物学];
学科分类号
071009 ; 090102 ;
摘要
In the late third larval instar of Drosophila melanogaster, the prothoracic gland, an endocrine portion of the ring gland, synthesizes ecdysteroids at an accelerated rate. The resultant ecdysteroid titer peak initiates the events associated with metamorphosis. The normal prothoracic gland displays several ultrastructural features at this developmental stage that reflect increased steroidogenic activity, including extensive infoldings of the plasma membrane (membrane invaginations) and an increase in both the concentration of smooth endoplasmic reticulum (SER) (or transitional ER) and elongated mitochondria. By contrast, the prothoracic glands of larvae homozygous for a conditional larval lethal mutation, l(3)ecd1ts, not only fail to produce ecdysteroids at normal levels at the restrictive temperature (29-degrees-C), but also acquire abnormal morphological features that reflect the disruptive effects of the mutation. These abnormalities include an accumulation of lipid droplets presumed to contain sterol precursors of ecdysteroids, a disappearance of SER and a drastic reduction of membrane invaginations in the peripheral area of the cell. These morphological defects are observed in prothoracic glands dissected from larvae transferred from 18-degrees-C to 29-degrees-C approximately 24 h before observation and also within 4 h of an in vitro transfer to 29-degrees-C following dissection from wandering third instar larvae reared at 18-degrees-C. No ultrastructural abnormalities were noted in the corpus allatum portion of mutant ring glands. These observations further indicate the direct involvement of the ecd gene product in ecdysteroid synthesis and suggest a role for the gene in the proper transport of precursors to the site where they can be utilized in ecdysteroid biosynthesis.
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收藏
页码:435 / 445
页数:11
相关论文
共 50 条
[1]   A COMPARATIVE STUDY OF RING GLANDS FROM WILD TYPE AND 1(2)GL MUTANT DROSOPHILA MELANOGASTER [J].
AGGARWAL, SK ;
KING, RC .
JOURNAL OF MORPHOLOGY, 1969, 129 (02) :171-+
[2]  
ANDREIS PG, 1989, CELL TISSUE RES, V258, P43
[3]  
BIRKENBEIL H, 1983, CELL TISSUE RES, V229, P433
[4]   ECDYSONE LEVELS DURING METAMORPHOSIS OF DROSOPHILA-MELANOGASTER [J].
BORST, DW ;
BOLLENBACHER, WE ;
OCONNOR, JD ;
KING, DS ;
FRISTROM, JW .
DEVELOPMENTAL BIOLOGY, 1974, 39 (02) :308-316
[5]   CHOLESTEROL-METABOLISM IN THE ADRENAL-CORTEX [J].
BOYD, GS ;
MCNAMARA, B ;
SUCKLING, KE ;
TOCHER, DR .
JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY, 1983, 19 (01) :1017-1027
[6]  
BOYD GS, 1980, RECENTLY DISCOVERED, P95
[7]  
BROWN MS, 1980, J LIPID RES, V21, P505
[8]   METAMORPHOSIS OF THE CORPUS ALLATUM AND DEGENERATION OF THE PROTHORACIC GLANDS DURING THE LARVAL PUPAL ADULT TRANSFORMATION OF DROSOPHILA-MELANOGASTER - A CYTOPHYSIOLOGICAL ANALYSIS OF THE RING GLAND [J].
DAI, JD ;
GILBERT, LI .
DEVELOPMENTAL BIOLOGY, 1991, 144 (02) :309-326
[9]   STRUCTURAL ASPECTS OF MEMBRANE OF ENDOPLASMIC-RETICULUM [J].
DEPIERRE, JW ;
DALLNER, G .
BIOCHIMICA ET BIOPHYSICA ACTA, 1975, 415 (04) :411-472
[10]   CORRELATION BETWEEN MORPHOLOGY AND LIPID CONTENT OF ADRENAL CORTEX OF GUINEA-PIG, RAT, COW [J].
FRUHLING, J ;
SAND, G ;
PENASSE, W ;
PECHEUX, F ;
CLAUDE, A .
JOURNAL OF ULTRASTRUCTURE RESEARCH, 1973, 44 (1-2) :113-133