CHANGES IN NURSE CELL-NUCLEI DURING SYNCHRONOUS INFECTION WITH TRICHINELLA-SPIRALIS

The rate of enlargement of nuclei was determined on 4-mu-m-thick sections of synchronously infected mouse thigh muscle. Normal muscle nuclei had a geometric mean volume of 84-mu-m3 and a range of 42-170-mu-m3. At days 5, 6, 7, 8, and 10 and 6 mo after infection, mean nuclear volume was 177 (100-315)-mu-m3, 254 (140-462) mu-m3, 278 (172-447) mu-m3, 681 (407-1,138) mu-m3, 512 (326-804) mu-m3, and 509 (298-870) mu-m3, respectively. Size of nuclei for any given day followed a log normal distribution. On days 7 and 8 after infection, 31% of enlarged nuclei had 2 nucleoli, whereas only 15% had 2 nucleoli on day 10. One percent of enlarged nuclei in 6-mo-old nurse cells had double nucleoli. The number of enlarged nuclei in 6-mo-old nurse cells was determined from serial sections of infected tongue muscle. Each nurse cell contained an average of 40 enlarged nuclei. Sixty-four percent of nurse cells examined (n = 55) had between 30 and 60 enlarged nuclei. However, there was great variation in the range (7-142). These results are discussed in relation to the development of the nurse cell.