Reiterated sequences of herpes simplex virus type 1 (HSV-1) genome can serve as physical markers for the differentiation of HSV-1 strains

Abstract

The stability of regions containing tandemly reiterated sequences in the S component of the herpes simplex virus type 1 (HSV-1) genome was determined, by comparing restriction fragments of the regions among sets of HSV-1 isolates derived from a single source. The 6 reiterations examined were grouped into three. Reiteration VII (within protein coding regions of genes US10 and US11) and reiteration IV (within introns of genes US1 and US12) were stable between the isolates (group 1). Regions containing one of four other reiterations were detected as a set of ladder-like fragments. Reiteration II (between "a" sequence and IE 175 gene) and reiteration VI (within an intergenic region on the 3' side of the 3' co-terminal family of genes US10, US11, and US12) (group 3) were more unstable than reiteration I (within "a" sequence) and reiteration III (between "a" sequence and IE175 gene) (group 2). The mode of fluctuation of the reiterations observed within a set of HSV-1 strains isolated from an individual was similar to that observed between HSV-1 single-plaque clones separated in cultured cells. These reiterations, except for group 3, can serve as sensitive and convenient markers for differentiating HSV-1 strains.

Divergence of reiterated sequences in a series of genital isolates of herpes simplex virus type 1 from individual patients

“…4a, lanes 3 and 4). Differences in reiteration IV were detected for the first time in the present study between HSV-1 isolates which were isolated from the same patient and could not be distinguished in terms of RFLP variation (Umene & Yoshida, 1989, 1993Umene & Sakaoka, 1991). Reiteration I.…”

“…4a, lanes 1-4). Differences in reiteration IV were detected in two of the three multiple-recurrence sets but in none of the primary-recurrence sets; hence, the probability of detection of events relating to differences in reiteration IV seemed to be larger in multiple-recurrence sets than in primary-recurrence sets.Reiteration I was considered to be capable of serving as a marker for differentiating HSV-1 strains, since the major (or single) fragment containing reiteration I was the same size in single-plaque isolates (Umene, 1991;Umene & Yoshida, 1989). Differences in the major fragment of reiteration I between clinical isolates from the same patient were detected in multiple-recurrence sets 1 and 3, but not in primaryrecurrence sets (Fig.…”

“…1) (Umene & Yoshida, 1989). It was proposed that reiterations I, IV and VII can serve as sensitive and convenient markers for the differentiation of HSV-1 strains.…”

“…Epidemiologically unrelated HSV-1 strains can usually be differentiated by analysing variations in restriction endonuclease (RE) cleavage patterns (Buchman et al, 1978(Buchman et al, , 1980Chaney et al, 1983;Lonsdale et al, 1980). Variations in RE cleavage patterns between HSV-1 strains are divided into two types (Umene et al, 1984;Umene & Yoshida, 1989, 1993Umene, 1998a, b). One type of variation, termed 'restriction fragment length polymorphism' (RFLP), is due mostly to a gain or loss of an RE cleavage site and causes a simple change in RE cleavage patterns.…”

“…Thus, reiteration VII is assumed to be the most stable (Umene & Yoshida, 1989). In our previous study, differences in reiteration IV were not detected between single-plaque isolates and between clinical isolates from the same patient (Umene & Yoshida, 1989). However, significant differences in reiteration IV were detected in the present study between clinical isolates, which were isolated from the same patient and could not be distinguished in terms of RFLP variation (sets 1 and 2) (Fig.…”