94
 bees and belonged to a group of variants found at very high frequency in bees

 sampled from east Europe and North America. This was not surprising, as the

 library from which the original clone pB178 was obtained was constructed with

 DNA from bees of east European ancestry (Hall 1986).

 A few polymorphic Mspl sites were identified in 178. Additional Mspl

sites in each region of 178, not detected in Mspl digested of the probe DNA,

have been hypothesized to account for the fragments detected in other

variants, some of which are indicated in Figures 14 19. For example, the

M400 variants as a group were characterized by a unique 1.1kb fragment, but

lacked a 0.85kb fragment present in all of the other Mspl variants (Figure 1).

The results of the hybridization with 178P,K (Figure 15) demonstrated the

allelic relationship of the 1.1kb and 0.85kb fragments.

 M101, M103, and the M400s did not have a fragment around 0.27kb

which was observed in the other variants (smallest fragment shown in Figure

1). The Mspl sites which could account for the 1.1kb and 0.85kb fragments

were concluded to lie outside the probe region (Figure 15, sites a and b), in

which case the Mspl fragment representing the difference between these two

sites would not be detected by the probe. The site that accounts for the

0.27kb fragment seen in all variants except M101, M103, and the M400s

could then be located between sites c and d, or between sites e and h. The

pattern detected for M503 provided the answer; it contained 0.49kb and

0.27kb fragments, and did not contain a 0.38kb fragment. Site f, between