The Effect of Temperature on the Production of Perithecia by Neurospora crassa

Abstract

SUMMARYThe wild-type strains of Neurospora crmsa first isolated by Dodge, Abbott & Chilton were found to differ in the range of temperatures over which protoperithecia were produced; similar results were obtained with two recently isolated wild strains of a species of Neurospora. The ability to develop protoperithecia a t 30' was found to be controlled by at least two genes in reciprocal crosses between two wild types differing in this character. A correlation of these observations with the reported features of tyrosinase production is discussed. Certain mutant strains backcrossed repeatedly to a wild-type strain gave exceptional results at 30". Preliminary observations suggest that the part played by nicotinamide in the sexual cycle may be connected with some of these exceptions. Temperature did not obviously affect ascus development in outbred crosses between Lindegren and Abbott wild-type strains. With inbred crosses ascus development was controlled by several factors which were temperature sensitive and differed in degree of effect in reciprocal crosses. In most strains tested 20' was the optimum temperature for normal ascus development. At higher temperatures gross abnormalities were observed including asci with more than eight spores.

PHOTOINDUCTION OF PROTOPERITHECIA IN NEUROSPORA CRASSA BY BLUE LIGHT

“…Table 1 shows that at the constant fluence of 12.6 Jim' the physiological response is constant. These results confirm the reciprocity law for fluence rates from 5.25 x to 1 .OS Wim' and for exposure times from 12 to 240 s. It was already known that in Neurosporu the development of protoperithecia is affected by genetic factors (Viswanath-Reddy et al, 1977;Johnson, 1978) and environmental factors (McNelly-Ingle and Frost, 1965;Viswanath-Reddy and Turian, 1975). Our work indicates that in N .…”

The effect of temperature on recombination frequency inNeurospora crassa

“…The relationship between recombination frequency and temperature has been examined in several crosses over the maximum range (15° to 30°C.) at which the sexual cycle can be completed (McNelly-Ingle & Frost, 1965). Markers have been used in both Linkage Groups I and VI to determine if the temperature relationship is common or specific for the linkage group under test.…”

Multiple Alterations in Metabolite Uptake in a Mutant of Neurospora crassa

“…An interesting parallel exists between the growth habits of 55701 and the physiology of mating in Neurospora species. Formation of the unfertilized female fruiting body, the protoperithecium, normally fails to occur in wild type at temperatures above 30 C, or, if it occurs at all, it is markedly abnormal (17,25). This corresponds well to the observed temperature above which 55701 fails to grow.…”

“…However, Gross (16) found some years ago that such mixed mating type heterocaryons could be formed even on media which do not allow sexual differentiation, and exhibit complementation between nutritional deficiencies. Significantly, heterocaryotic conidia formed at 25 C, but only extremely rarely at 37 C from mixed mating type heterocaryons; moreover, it appears that the heterocaryons themselves did not grow at 37 C. No such temperature restriction was seen in heterocaryons that comprised only a single mating type. It would not be surprising to find that the mating type gene controlled elements of structure in both the plasma and nuclear membranes.…”