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The pattern of simian virus 40 (SV40) deoxyribonucleic acid transcription has been examined in 11 SV40-transformed cell lines. In all cases, substantial regions of the minus strand (35-75%) appeared to be transcribed. In the lines tested, these regions included the “early” gene sequences. The SV40-specific ribonucleic acid from at least two of the transformed cell lines represented significantly greater portions of the minus strand than are represented in “early” lytic ribonucleic acid. Small regions of the plus strand appeared to be transcribed in only two of the transformed cell lines.

Small amounts of fractionated, denatured, 32P-labeled DNA from SV40 virus were incubated with a large excess of the complementary RNA of SV40 prepared in vitrowith Escherichia coliRNA polymerase; the viral DNA strands were separated on hydroxyapatite columns. The RNA present in green monkey cells late in the lytic cycle reacted with 40-42% of the strand complementary to the in vitrocomplementary RNA (minus strand), and 60-64% of the opposite (plus) strand. “Early lytic” RNA failed to significantly interact with the plus strand, but formed stable duplex molecules with 35-39% of the minus strand. The RNA prepared from mouse embryo cells 24 hr after infection with SV40 combined with 35-38% of the minus strand and 60-62% of the plus strand. In all cases, the same regions of either the plus or minus strand appear to be transcribed in permissive and nonpermissive infections.

The size distribution of polyribosome-associated simian virus 40 (SV40) ribonucleic acid (RNA) was examined at various times after productive infection. Eight hours after infection, virus-specific RNA was detected in the 14 to 17Sregion of a sucrose gradient by deoxyribonucleic acid (DNA)-RNA hybridization; RNA present in fractions sedimenting more rapidly did not react with SV40 DNA. At successively later times, SV40 RNA was detected in more rapidly sedimenting regions. By 24 hr, a portion of the SV40 RNA was detected in the 28Sregion, sedimenting slightly more rapidly than a MS2 RNA marker. Nuclear SV40 RNA, prepared from cells 48 hr after infection, was distributed in more rapidly sedimenting regions of the gradient, peaking at about 32 to 34S. Some nuclear virus-specific RNA could be detected in the 45 to 50Sregion. During the abortive infection of mouse cells, the sedimentation profile of SV40 RNA was very similar to that observed during the early phases of the lytic cycle.

This study investigated the effect, on conversational speech, of a training task that included correct sound production of words as a subject read a word list at increasing rates of speed. Five children participated in a 10-day program designed to automatize articulation of a target souncf. The /s/ was the target for three children and the /r/ for two. At each training session a subject was required to read a list of 60 words, 25 times. The child was rewarded each time he read the list within a prescribed time period while producing every target sound correctly. Probes of conversational speech were recorded each day in school, at home, and in a third setting at the conclusion of the program. Analyses of these tapes indicated that four of the five children showed varying degrees of carryover. Complete carryover, however, was not achieved. Subjects who made the greatest improvement tended to have the highest number of correct readings, as well as the most rapid readings of the word list. Recordings made in the home, school, and in a third environment reflected similar trends of carryover.

This project studied auditory abilities of a selected group of advanced and retarded third-grade readers from high and low socioeconomic environments. Two general hypotheses were posed: (1) advanced and retarded readers perform differently on auditory tasks; and (2) socioeconomic environment affects auditory ability. A one-hour battery of auditory tests was administered to 39 third-grade children, all of whom were at least one year ahead or one year behind grade level in reading achievement. This research indicated that significant differences existed between advanced and retarded readers on the auditory tasks. Socioeconomic environment, alone, did not affect auditory ability. The advanced readers from both levels performed similarly, and so did the retarded readers. Significant differences were more frequently found when the groups had more widely divergent mean IQ scores.