86
for 178P,E1 location and size). Analysis of the sequences of the ends of

subclone pG178PE, revealed a Ddel site at 150bp from the Pstl site (Figures

20 & 21). The Ddel fragments to which 178PK hybridized are shown in Figure

21. In the majority of variants, 178P,K hybridized to a fragment of

approximately 0.75kb, and another fragment of approximately 1.3kb. In the

D100 and D200 variants, a single fragment of approximately 2.1kb was

detected. The loss of the Ddel site at approximately 1450bp would account

for the 2.1kb fragment in the D100 and D200 variants. The variation in the

size of the fragment of approximately 1.3kb may be the result of length

polymorphism(s) closer to the Pstl1 site.

 There were no Ddel sites within 178KH. A single fragment in each

variant, approximately 2.0kb, was detected when 178KH was used to probe

this region, shown in Figure 22. On the basis of the Ddel sites identified in

178P,K, it was concluded that the same 2.0kb fragment had been detected by

178P,K and 178KH, and would be detected by 178HB as well. The placement

of the Ddel sites on either side of 178KH is shown in Figure 22.

 Digestion of 178HB with Ddel resulted in fragments of approximately

1.15kb and 0.75kb. The Ddel fragments to which 178HB hybridized are

shown in Figure 23. In each variant, 178HB hybridized to the 2.0kb fragment

detected by 178P,K and 178KH. One other fragment was detected by 178HB

in each variant: approximately 1.0kb in the D100s and D400s, 1.25kb in the

D200s and D300s, and 0.98kb in the D500s. Two possible locations for a site