FLIGHT MUSCLE CHANGES IN BLACK HILLS BEETLES, DENDROCTONUS PONDEROSAE (COLEOPTERA: SCOLYTIDAE), DURING EMERGENCE AND EGG LAYING

1969 ◽  
Vol 101 (5) ◽  
pp. 507-512 ◽  
Author(s):  
W. F. McCambridge ◽  
S. A. Mata

AbstractThe lateralis medius, an indirect flight muscle of Black Hills beetles, degenerated abruptly in females within 3 days after attack. Egg laying began at the end of the 3 days. Thickness of the muscle changed much more than width. Regeneration began in most ovipositing females about 10 days after attack. Steady development of the muscle to its maximum size, reached prior to beetle emergence, offers a method of forecasting emergence.

2017 ◽  
Vol 312 (2) ◽  
pp. C111-C118 ◽  
Author(s):  
Cuiping Zhao ◽  
Douglas M. Swank

Stretch activation (SA) is a delayed increase in force that enables high power and efficiency from a cyclically contracting muscle. SA exists in various degrees in almost all muscle types. In Drosophila, the indirect flight muscle (IFM) displays exceptionally high SA force production ( FSA), whereas the jump muscle produces only minimal FSA. We previously found that expressing an embryonic (EMB) myosin heavy chain (MHC) isoform in the jump muscle transforms it into a moderately SA muscle type and enables positive cyclical power generation. To investigate whether variation in MHC isoforms is sufficient to produce even higher FSA, we substituted the IFM MHC isoform (IFI) into the jump muscle. Surprisingly, we found that IFI only caused a 1.7-fold increase in FSA, less than half the increase previously observed with EMB, and only at a high Pi concentration, 16 mM. This IFI-induced FSA is much less than what occurs in IFM, relative to isometric tension, and did not enable positive cyclical power generation by the jump muscle. Both isometric tension and FSA of control fibers decreased with increasing Pi concentration. However, for IFI-expressing fibers, only isometric tension decreased. The rate of FSA generation was ~1.5-fold faster for IFI fibers than control fibers, and both rates were Pi dependent. We conclude that MHC isoforms can alter FSA and hence cyclical power generation but that isoforms can only endow a muscle type with moderate FSA. Highly SA muscle types, such as IFM, likely use a different or additional mechanism.


Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 123-143
Author(s):  
Takao Koana ◽  
Yoshiki Hotta

Since animal behaviour is executed through neuronal circuits including sensory receptors and muscle, genes vital for their development and differentiation must be found among mutants having behavioural anomaly. After mutagenesis with ethyl methanesulphonate (EMS), we screened for X-linked flightless mutants of Drosophila melanogaster by using a column-type flight tester. Approximately 104 individuals were screened and 21 mutant genes were isolated. Chromosomal mapping and complementation experiments revealed that they belong to 15 cistrons randomly located on X chromosome, three cistrons having more than two alleles. Two of the isolated mutants (AtO2 and AtH, which are recessive both behaviourally and morphologically) were analysed with the mosaic fate mapping technique, and both were found to have their primary foci in mesodermal region of blastoderm, suggesting that the genes exert their primary effect in indirect flight muscle. Electronmicroscopic studies on the muscles from four alleles of the AtO2 cistron revealed an abnormality in myofibrillar arrangement. A possible deficit within Z-band components is discussed in relation to wings-up B mutants. The indirect flight muscle of AltH was also examined, and it was found that sarcomere length and diameter of myofibrils were abnormal. It was postulated that a possible factor which controls size of myofibrils is defective in this mutant. These examples indicate the advantage of combining ultrastructural examination with genetic mosaic mapping technique.


1988 ◽  
Vol 107 (6) ◽  
pp. 2601-2612 ◽  
Author(s):  
P T O'Donnell ◽  
S I Bernstein

We have determined the molecular defect of the Drosophila melanogaster myosin heavy chain (MHC) mutation Mhc and the mutation's effect on indirect flight muscle, jump muscle, and larval intersegmental muscle. We show that the Mhc1 mutation is essentially a null allele which results in the dominant-flightless and recessive-lethal phenotypes associated with this mutant (Mogami, K., P. T. O'Donnell, S. I. Bernstein, T. R. F. Wright, C. P. Emerson, Jr. 1986. Proc. Natl. Acad. Sci. USA. 83:1393-1397). The mutation is a 101-bp deletion in the MHC gene which removes most of exon 5 and the intron that precedes it. S1 nuclease mapping indicates that mutant transcripts follow two alternative processing pathways. Both pathways result in the production of mature transcripts with altered reading frames, apparently yielding unstable, truncated MHC proteins. Interestingly, the preferred splicing pathway uses the more distal of two available splice donor sites. We present the first ultrastrutural characterization of a completely MHC-null muscle and show that it lacks any discernable thick filaments. Sarcomeres in these muscles are completely disorganized suggesting that thick filaments play a critical role in sarcomere assembly. To understand why the Mhc1 mutation severely disrupts indirect flight muscle and jump muscle function in heterozygotes, but does not seriously affect the function of other muscle types, we examined the muscle ultrastructure of Mhc1/+ heterozygotes. We find that these organisms have a nearly 50% reduction in the number of thick filaments in indirect flight muscle, jump muscle, and larval intersegmental muscle. In addition, aberrantly shaped thick filaments are common in the jump muscle and larval intersegmental muscle. We suggest that the differential sensitivity of muscle function to the Mhc1 mutation is a consequence of the unique myofilament arrays in each of these muscles. The highly variable myofilament array of larval intersegmental muscle makes its function relatively insensitive to changes in thick filament number and morphology. Conversely, the rigid double hexagonal lattice of the indirect flight muscle, and the organized lattice of the jump muscle cannot be perturbed without interfering with the specialized and evolutionarily more complex functions they perform.


1991 ◽  
Vol 222 (4) ◽  
pp. 963-982 ◽  
Author(s):  
John Sparrow ◽  
Mary Reedy ◽  
Elizabeth Ball ◽  
Vassilis Kyrtatas ◽  
Justin Molloy ◽  
...  

2019 ◽  
Vol 116 (3) ◽  
pp. 404a
Author(s):  
Nadia Daneshparvar ◽  
Dianne Taylor ◽  
Hamidreza Rahmani ◽  
Kenneth A. Taylor

1988 ◽  
Vol 107 (6) ◽  
pp. 2613-2621 ◽  
Author(s):  
M Chun ◽  
S Falkenthal

Using a combination of molecular and genetic techniques we demonstrate that Ifm(2)2 is an allele of the single-copy sarcomeric myosin heavy chain gene. Flies homozygous for this allele accumulate wild-type levels of mRNA and protein in tubular muscle of adults, but fail to accumulate detectable amounts of myosin heavy chain mRNA or protein in the indirect flight muscle. We propose that the mutation interferes with either transcription of the gene or splicing of the primary transcript in the indirect flight muscle and not in other muscle tissues. Biochemical and electron microscopic analysis of flies homozygous for this mutation has revealed that thick filament assembly is abolished in the indirect flight muscle resulting in the instability of wild-type thick filament proteins. In contrast, thin filament and Z disc assembly are marginally affected. We discuss a working hypothesis for sarcomere assembly and define and experimental approach to test the predictions of this proposed pathway for sarcomere assembly.


1970 ◽  
Vol 102 (6) ◽  
pp. 705-713 ◽  
Author(s):  
J. M. Schmid

AbstractThe number of Medetera aldrichii Wheeler adults emerging daily in 1966 and 1967 was low and irregular. Peak numbers apparently emerged 20–30 days prior to mass emergence of Dendroctonus ponderosae Hopkins although the numbers fluctuated through the mass emergence period of the beetle. Densities of emerging adults averaged less than 1 per square foot of bark and never exceeded 6.0 per square foot. Densities of the emerging flies and beetles did not appear related.Adults mated on the bark surface of trees infested with D. ponderosae; mating habits are described.Females oviposited in degenerate resin ducts in the bark surface. Two eggs per duct were the modal number. Seven or more per duct were found in less than 5% of the ducts examined.


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