Modified dot-blot hybridization technique for filamentous fungi.

Colony hybridization (Grunstein & Hogness, 1975 Proc. Nat. Acad. Sci. USA 72:3961-3965) A allows the rapid screening of multiple strains for the presence or absence of particular DNA sequences

A rapid and efficient approach for Neurospora crassa transformation using low melting point agarose purified DNA.

A rapid and efficient approach for Neurospora crassa transformation using low melting point agarose purified DNA

The Clock affecting 1 mutation of Neurospora is a recurrence of the frq\u3csup\u3e7\u3c/sup\u3e mutation7

The clock affecting-1 (cla-1) mutation of Neurospora crassa increases the period and decreases temperature compensation of the circadian rhythm, and was thought to define an uncloned gene with a possible role in the Neurospora clock. This defect, thought to be due to a translocation, was associated with a slow growth rate and a period of about 27 h at 25cla-1 and found the growth rate and period defects to be due to linked independent mutations. The translocation was not the cause of the long period. The csp-1 mutation, present in the original cla-1 strain, had a period shortening effect, thus cla-1 strains lacking csp-1 had a period length similar to that of frequency7 (frq7). The cla-1 period defect mapped to the frq locus, and sequencing of frq revealed cla-1 to be a re-isolation of frq7

Growth and Structure of Stochastic Sequences

We introduce a class of stochastic integer sequences. In these sequences, every element is a sum of two previous elements, at least one of which is chosen randomly. The interplay between randomness and memory underlying these sequences leads to a wide variety of behaviors ranging from stretched exponential to log-normal to algebraic growth. Interestingly, the set of all possible sequence values has an intricate structure.Comment: 4 pages, 4 figure

Alternative Use of DNA Binding Domains by the Neurospora White Collar Complex Dictates Circadian Regulation and Light Responses

In the Neurospora circadian system, the White Collar complex (WCC) of WC-1 and WC-2 drives transcription of the circadian pacemaker gene frequency (frq), whose gene product, FRQ, as a part of the FRQ-FRH complex (FFC), inhibits its own expression. The WCC is also the principal Neurospora photoreceptor; WCC-mediated light induction of frq resets the clock, and all acute light induction is triggered by WCC binding to promoters of light-induced genes. However, not all acutely light-induced genes are also clock regulated, and conversely, not all clock-regulated direct targets of WCC are light induced; the structural determinants governing the shift from WCC\u27s dark circadian role to its light activation role are poorly described. We report that the DBD region (named for being defective in binding DNA), a basic region in WC-1 proximal to the DNA-binding zinc finger (ZnF) whose function was previously ascribed to nuclear localization, instead plays multiple essential roles assisting in DNA binding and mediating interactions with the FFC. DNA binding for light induction by the WCC requires only WC-2, whereas DNA binding for circadian functions requires WC-2 as well as the ZnF and DBD motif of WC-1. The data suggest a means by which alterations in the tertiary and quaternary structures of the WCC can lead to its distinct functions in the dark and in the light

Historical microbiology: revival and phylogenetic analysis of the luminous bacterial cultures of M . W . B eijerinck

Luminous bacteria isolated by M artinus W . B eijerinck were sealed in glass ampoules in 1924 and 1925 and stored under the names P hotobacterium phosphoreum and ‘ P hotobacterium splendidum ’. To determine if the stored cultures were viable and to assess their evolutionary relationship with currently recognized bacteria, portions of the ampoule contents were inoculated into culture medium. Growth and luminescence were evident after 13 days of incubation, indicating the presence of viable cells after more than 80 years of storage. The B eijerinck strains are apparently the oldest bacterial cultures to be revived from storage. Multi‐locus sequence analysis, based on the 16S rRNA , gapA , gyrB , pyrH , recA , luxA , and luxB genes, revealed that the B eijerinck strains are distant from the type strains of P . phosphoreum , ATCC 11040 T , and V ibrio splendidus , ATCC 33125 T , and instead form an evolutionarily distinct clade of V ibrio . Newly isolated strains from coastal seawater in N orway, F rance, U ruguay, M exico, and J apan grouped with the B eijerinck strains, indicating a global distribution for this new clade, designated as the beijerinckii clade. Strains of the beijerinckii clade exhibited little sequence variation for the seven genes and approximately 6300 nucleotides examined despite the geographic distances and the more than 80 years separating their isolation. Gram‐negative bacteria therefore can survive for many decades in liquid storage, and in nature, they do not necessarily diverge rapidly over time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88047/1/fem1177.pd