KORNFIELD AND BOGDANOWICZ: MITOCHONDRIAL DNA IN ATLANTIC HERRING 



Samples were digested with 16 six-base restric- 

 tion endonucleases (Table 1 ) under conditions rec- 

 ommended by suppliers (Bethesda Research 

 Labs, New England Biolabs). Just prior to addi- 

 tion of restriction enzymes, samples were incu- 

 bated with Ribonuclease A (RNase) at 60°C for 5 

 minutes and allowed to cool to 37°C. Restriction 

 fragments were separated by horizontal elec- 

 trophoresis in 1% agarose gels. Hindlll digests of 

 lambda DNA were used as molecular weight 

 standards on all gels. Gels were stained for 60 

 minutes with 0.5 g L~^ ethidium bromide and 

 destained for 30 minutes in 5 mM MgS04 prior to 

 photography. The relative mobilities of mtDNA 

 and lambda fragments were measured from pho- 

 tographs with a stereomicroscope. Molecular 

 weights of restriction fragments were calculated 

 from least squares third order polynomial regres- 

 sions of log- transformed lambda fragment mobili- 

 ties. 



RESULTS 



Restriction digests of mtDNAs prepared by the 

 rapid phenol extraction procedure well resolved, 

 repeatable digestion patterns (Fig. 2). Two en- 

 zymes. Bam HI and Sail did not digest the her- 

 ring mtDNA molecule. Variant digestion pat- 

 terns were noted for the majority of enzymes 

 examined (Table 1) and were common both within 



Figure 2. — Ethidium bromide stained agarose gel of mtDNA 

 digestion patterns of Atlantic herring, Clupea harengus (lanes 

 2-8). Samples were digested with BstYAl llanes 2, 3; phenotypes 

 B, C), £co RI (lanes 4, 5; phenotypes A, C), and fig/ II (lanes 6, 7; 

 phenotypes A, B). Standard (lanes 1, 8) is a //mdlll digest of 

 lambda DNA. 



Table 1. — Digestion patterns of Atlantic herring mtDNA produced by six-base restriction endonucleases^. Superscripts denote homolo- 

 gous fragments, measured independently. 



Apa\ 



BstEW 



BgtW 



B 



H 



I 



B 



B 



8,800a 8,800a 



7,200e 6,100= 



900ti 960d 



900b 



7,200e 

 5,300 

 3,450 

 900b 



6,350 



6,100c 



2,450^1 



960d 



900b 



8,800a 

 7,200e 

 1,100 



7,350 

 6,100= 

 2,450b 

 900b 



1 1 ,830d 



4,670a 



550b 



10,820d 



4,670a 



1,1 60C 



550b 



15,160 

 1,150= 

 550b 



12,200 

 4,700a 



1 1 ,700d 

 3,650 

 1,340 

 550b 



9,940 

 4,1 30a 

 1 ,990b 

 1,270= 



6,590d 14,000 

 4, 1803 1,990b 

 3,230e 1,270= 

 1 ,960b 

 1 ,220= 



16,900 16,760 16,850 16,760 17,100 16,800 17,050 17,200 16,860 16,900 17,240 17,330 



Dra\ 



EcoRI 



EcoRV 



B 



B 



B 



7,600 

 3,700 

 2,570a 

 2J310b 



11,370 

 2,530a 

 2,290b 



9,460a 



4,220 



3,010b 



14,020 

 3,130b 



9,400a 

 7,250 



16,170 16,190 16,690 17,150 16,650 

 PvuW 



8,680a 



6,000 



2,230b 



16,910 

 Sac\ 



8,200 

 6,490 

 2,030 

 1,000 

 17,720 



8,600a 

 8,200 



16,800 

 Xba\ 



14,500 

 2,270b 



16,770 



H/ndlil 



A 

 13,500 



2,820 



1,000 



17,320 

 Xho\ 



17,180 17,260 



Kpn\ 



A 8 



15,200 17,000 

 1,910 



17,110 17,000 



^Two additional enzymes, Bamh\ and Sail produced no (or one) cuts. 



6,600d 



3,900 



3,250e 



1,970b 



1 ,220 = 



16,940 



Pst\ 



A 



10,790 



5,850 



16,640 

 Xmn\ 



563 



