The genetic control of the distinction between fat body and gonadal mesoderm in Drosophila

Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 713-723 ◽  
Author(s):  
V. Riechmann ◽  
K.P. Rehorn ◽  
R. Reuter ◽  
M. Leptin

The somatic muscles, the heart, the fat body, the somatic part of the gonad and most of the visceral muscles are derived from a series of segmentally repeated primordia in the Drosophila mesoderm. This work describes the early development of the fat body and its relationship to the gonadal mesoderm, as well as the genetic control of the development of these tissues. Segmentation and dorsoventral patterning genes define three regions in each parasegment in which fat body precursors can develop. Fat body progenitors in these regions are specified by different genetic pathways. Two regions require engrailed and hedgehog for their development while the third is controlled by wingless. decapentaplegic and one or more unknown genes determine the dorsoventral extent of these regions. In each of parasegments 10–12 one of these regions generates somatic gonadal precursors instead of fat body. The balance between fat body and somatic gonadal fate in these serially homologous cell clusters is controlled by at least five genes. We suggest a model in which tinman, engrailed and wingless are necessary to permit somatic gonadal develoment, while serpent counteracts the effects of these genes and promotes fat body development. The homeotic gene abdominalA limits the region of serpent activity by interfering in a mutually repressive feed back loop between gonadal and fat body development.

Development ◽  
1997 ◽  
Vol 124 (15) ◽  
pp. 2915-2922 ◽  
Author(s):  
V. Riechmann ◽  
U. Irion ◽  
R. Wilson ◽  
R. Grosskortenhaus ◽  
M. Leptin

The primordia for heart, fat body, and visceral and somatic muscles arise in specific areas of each segment in the Drosophila mesoderm. We show that the primordium of the somatic muscles, which expresses high levels of twist, a crucial factor of somatic muscle determination, is lost in sloppy-paired mutants. Simultaneously, the primordium of the visceral muscles is expanded. The visceral muscle and fat body primordia require even-skipped for their development and the mesoderm is thought to be unsegmented in even-skipped mutants. However, we find that even-skipped mutants retain the segmental modulation of the expression of twist. Both the domain of even-skipped function and the level of twist expression are regulated by sloppy-paired. sloppy-paired thus controls segmental allocation of mesodermal cells to different fates.


Genetics ◽  
1989 ◽  
Vol 121 (3) ◽  
pp. 517-525 ◽  
Author(s):  
A Shearn

Abstract Mutations in the ash-1 and ash-2 genes of Drosophila melanogaster cause a wide variety of homeotic transformations that are similar to the transformations caused by mutations in the trithorax gene. Based on this similar variety of transformations, it was hypothesized that these genes are members of a functionally related set. Three genetic tests were employed here to evaluate that hypothesis. The first test was to examine interactions of ash-1, ash-2 and trithorax mutations with each other. Double and triple heterozygotes of recessive lethal alleles express characteristic homeotic transformations. For example, double heterozygotes of a null allele of ash-1 and a deletion of trithorax have partial transformations of their first and third legs to second legs and of their halteres to wings. The penetrance of these transformations is reduced by a duplication of the bithorax complex. The second test was to examine interactions with a mutation in the female sterile (1) homeotic gene. The penetrance of the homeotic phenotype in progeny from mutant mothers is increased by heterozygosis for alleles of ash-1 or ash-2 as well as for trithorax alleles. The third test was to examine the interaction with a mutation of the Polycomb gene. The extra sex combs phenotype caused by heterozygosis for a deletion of Polycomb is suppressed by heterozygosis for ash-1, ash-2 or trithorax alleles. The fact that mutations in each of the three genes gave rise to similar results in all three tests represents substantial evidence that ash-1, ash-2 and trithorax are members of a functionally related set of genes.


Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 3-4
Author(s):  
Anne McLaren

In the first two papers of this volume, the genetic control of sex determination in Caenorhabditis and Drosophila is reviewed by Hodgkin and by Nöthiger & Steinmarin-Zwicky, respectively. Sex determination in both cases depends on the ratio of X chromosomes to autosomes, which acts as a signal to a cascade of règulatory genes located either on autosomes or on the X chromosome. The state of activity of the last gene in the sequence determines phenotypic sex. In the third paper, Erickson & Tres describe the structure of the mouse Y chromosome and the polymorphisms that have been detected in different mouse species and strains. As in all mammals, the Y carries the primary male-determining locus; autosomal genes may also be involved in sex determination, but they must act down-stream from the Y-linked locus.


1947 ◽  
Vol 45 (4) ◽  
pp. 413-416 ◽  
Author(s):  
E. M. Brieger ◽  
C. F. Robinow

In a cytological investigation of three branching and two non-branching strains grown on Loewenstein medium, it was found that avian tubercle bacilli contain chromatinic material which gives a positive Feulgen reaction and is readily stainable with Giemsa's solution after treatment of the fixed bacteria with hydrochloric acid.Growing filamentous forms of both ‘bacterial’ and ‘mycelial’ strains from 1 to 2 day old cultures contain variable numbers of irregularly spaced, more or less spherical chromatinic bodies which vary in staining in the same bacillus, some being red, others purple. During the third or fourth day the chromatinic material in the bacteria increases very much until most of it is fused into an almost homogeneous deeply stained column. In thenon-branchingstrains the filamentous forms with high chromatin content soon break up into small mono-or binucleate elements, and the same holds true for the ‘straight’ filamentous forms which are also present in cultures of branching strains. The ‘mycelial’ forms, on the other hand, disintegrate at this time (fourth or fifth day of cultivation), and it is uncertain whether they contribute (by partial fragmentation) to the masses of small mono- or binucleate forms which are the predominant element in old cultures of all the strains investigated.The chromatinic structures of avian tubercle bacilli have the same staining properties as those of ordinary non-acid-fast bacteria but differ from them in their behaviour during the early development of the bacilli.


Parasitology ◽  
1983 ◽  
Vol 86 (1) ◽  
pp. 147-160 ◽  
Author(s):  
J. H. Ali ◽  
J. Riley

SUMMARYThe life-cycles of two closely related cephalobaenid pentastomids, Raillietiella gehyrae and Raillietiella frenatus, which utilize geckos as definitive hosts and cockroaches as intermediate hosts, have been investigated in detail. Early development in the fat-body of cockroaches involves 2 moults to an infective, 3rd-stage larva which appears from 42–44 days post-infection. Complete development in geckos involves a further 5 moults in the case of males and 6 for females. Males mature precociously and copulation is a once-in-a-lifetime event which occurs around day 80 post-infection when both sexes are the same size but the uterus of the female is undeveloped. Sperm, stored in the spermathecae, is used to fertilize oocytes which slowly accumulate in the developing saccate uterus. Patency commences when the uterus carries approximately 4000–5500 eggs but only 25–36 % of these contain fully developed primary larvae. Since only mature eggs are deposited, we postulate that the vagina (?) of the female must be equipped with a selective filter that allows through large eggs but retains smaller, immature eggs. Thus the only limit on fecundity is the total number of sperms in the spermathecae and this is precisely the same factor that constrains egg production in the advanced order Porocephalida.


Development ◽  
1986 ◽  
Vol 91 (1) ◽  
pp. 251-266
Author(s):  
Peter A. Lawrence ◽  
Paul Johnston

Adult Drosophila mosaics can be used to study cell lineage and to map relative positions of primordia at the blastoderm stage. This information can define which germ layer an organ comes from and can help build models of genetic regulation of development. Here we use the sdh cell marker to map internal organs in mosaics made by nuclear transplantation. We confirm that oenocytes arise from the same progenitors as the adult epidermis, but that muscles and fat body have a separate (mesodermal) origin and that the precursors of epidermis and central neurones are closely intermingled in the ventral, but not dorsal, epidermis. We find that the malpighian tubules are more closely related to the hindgut than the midgut and are therefore ectodermal in origin. We find that each intersegmental muscle in the thorax arises from one specific parasegment in the embryo, but that very small numbers of myoblasts wander and contribute to muscles of inappropriate segments. We present evidence indicating that the visceral muscles of the midgut have a widely dispersed origin (over much of the embryo) while the somatic mesoderm of the female gonad comes from a small number of abdominal segments. The visceral mesoderm of the hindgut develops from a localized posterior region of the embryo.


Development ◽  
1998 ◽  
Vol 125 (5) ◽  
pp. 837-844 ◽  
Author(s):  
L.A. Moore ◽  
H.T. Broihier ◽  
M. Van Doren ◽  
R. Lehmann

During gastrulation, the Drosophila mesoderm invaginates and forms a single cell layer in close juxtaposition to the overlying ectoderm. Subsequently, particular cell types within the mesoderm are specified along the anteroposterior and dorsoventral axes. The exact developmental pathways that guide the specification of different cell types within the mesoderm are not well understood. We have analyzed the developmental relationship between two mesodermal tissues in the Drosophila embryo, the gonadal mesoderm and the fat body. Both tissues arise from lateral mesoderm within the eve domain. Whereas in the eve domain of parasegments 10–12 gonadal mesoderm develops from dorsolateral mesoderm and fat body from ventrolateral mesoderm, in parasegments 4–9 only fat body is specified. Our results demonstrate that the cell fate decision between gonadal mesoderm and fat body identity within dorsolateral mesoderm along the anteroposterior axis is determined by the combined actions of genes including abdA, AbdB and srp; while srp promotes fat body development, abdA allows gonadal mesoderm to develop by repressing srp function. Furthermore, we present evidence from genetic analysis suggesting that, before stage 10 of embryogenesis, gonadal mesoderm and the fat body have not yet been specified as different cell types, but exist as a common pool of precursor cells requiring the functions of the tin, zfh-1 and cli genes for their development.


Sign in / Sign up

Export Citation Format

Share Document