7734

• UCREFRP Catalog Number: 7734
• Author: Buth, D. G., Thomas R. Haglund and Sabrina Drill.
• Title: Preliminary Report on Razorback Suckers from Etter Pond.
• USFW Year: 1993.
• USFW - Doc Type: Los Angeles, CA.
• Copyright Material: NO

to that in Etter Pond (Figure 1 --- based on 13 Etter Pond
specimens). That Etter Pond had been chosen as a source for
breeding stock seemed to us to be an extraordinary stroke of bad
luck given that it was found to be the population highest in
genomic pollution. These findings were taken "on the road" in
June 1993 and presented at annual meetings of the American
Society of Ichthyologists and Herpetologists, the Southern
California Academy of Sciences, and the Society for Conservation
Biology. Additional study was deemed necessary.
RESULTS AND DISCUSSION
Tissue samples from an additional 42 specimens from Etter
Pond were obtained and examined electrophoretically. A full
screening of all loci was conducted so that all these specimens
could be included in our original database. Results for the four
marker loci are provided in Table 1. These findings confirm
those from the original 13 specimens. All 42 were heterozygous
for razorback and flannelmouth alleles at Ck-A or were homozygous
for the flannelmouth allele. It is surprising that NONE of the
55 Etter Pond razorbacks expressed the razorback Ck-A allele in
the homozygous condition (perhaps this combination is now not
favored in this new genome mixture). To a far lesser degree,
introgressive allelic combinations were identified at mIcdh-A,
mMdh-A1 and Ada-A2 but no F1 individuals were identified.
Results for expression at the four marker loci for specimens
from other Colorado localities are presented in Table 2. The
original 1990 sample of four specimens from Highline Lake and the
1988 sample of three specimens from the Colorado River proper
showed no evidence of genetic interaction with flannelmouth
suckers. However, the 1991 specimen obtained from a pond
adjacent to the Colorado River was homozygous for the
flannelmouth Ck-A allele, and all three specimens obtained from
the Colorado River (?) in 1993 had flannelmouth Ck-A (one of the
latter was also heterozygous at Ada-A2).
The intact specimen sent (7F7D7D2B5E - Horsethief mortality)
expressed only razorback alleles at the marker loci (Table 2).
This expression is not surprizing for mIcdh-A, mMdh-A1, or Ada-A2
in which introgressed alleles are uncommon and the chance of two
parents lacking introgressed alleles at these loci is high.
However, the "unusual" expression of only razorback alleles at
Ck-A is probably just a function of the recombination at Ck-A
from the cross of two heterozygous parents:
RF x RF = 1/4 RR, 1/2 RF, 1/4 FF
The creatine kinase marker.- It might be argued that the
"flannelmouth Ck-A allele" identified in the Etter Pond
razorbacks has a product with a coincident electrophoretic
mobility with that diagnostic for flannelmouth suckers; i.e. not
a marker for hybridization. In this scenario, this allele just