Human apolipoprotein A-I and C-III genes reside in the p11 → q13 region of chromosome 11

14,

Februory

AND BIOPHYSICAL RESEARCH COMMUNICATIONS Pages 934-942

BIOCHEMICAL

Vol. 118, No. 3, 1984 1984

HUMAN APOLIPOPROTEIN A-I AND C-III GENES RESIDE IN THE pll+q13 REGION OF CHROMOSOME 11

S. W. Law', G. Gray', H. 6. Brewer, Jr.1, 2 A. Y. Sakaguchi, and S. L. Naylor' 1 Molecular 2

Received

Disease National

Department

January

Branch, Institutes

National Heart, Lung, and Blood of Health, Bethesda, Maryland

of Human Genetics, Buffalo,

Roswell Park New York

Memorial

Institute

Institute

4, 1984

SUMMARY: Apolipoprotein (apol A-l is a major protein of high density lipoms (HDL). The gene for apoA-I has been localized to the pll + q13 regjon of chromosome 11 by filter hybridization analysis of mouse-human hybrid cell cDNAs containing chromosome 11 translocations utilizing a cloned human apoA-I cDNA probe. The known linkage of apoA-I and apoC-II I also permitted the simultaneous assignment of the apoC-III gene to the same region on chromosome 11. Comparison with previously established gene linkages on the mouse and human genome suggests that apoA-I + apoC-III may be linked to the esterase A4 and uroporphyrinogen synthase genes which are present on the long arm of human chromosome 11. The localization of the apoA-I + apoC-I II genes in the pll+ql3 region of chromosome 11 represents a definitive chromosomal assignment of a human apolipoprotein gene, and will now enable more detailed analysis of the geneomic organization and linkages of the apolipoprotein genes.

Plasma separated

lipoproteins, by hydrated

the density

into

VLDL , IDL,

LDL, and HDL (1).

proportions

of triglycerides,

and proteins

reviews,

'Abbreviations:

plasma

low

TBE,

are

Tris

934

composed

esters,

of varying

phospholipids,

have

been

isolated

have been for

LDL, low

lipoproteins;

borate

chylomicrons,

as cofactors

lipoproteins; density

in man, can be

designated

and several

function

$1.50 Inc. reserved.

lipoproteins

lipoproteins

pH 7.1.

0 1984 by Academic Press. qf reproduction in any form

classes

transport

apolipoproteins

density

HDL, high

lipid

cholesteryl

Apolipoproteins

Kb, kilobase;

Copyright A// rights

major

Thirteen

VLDL, very

citrate,

for

cholesterol,

proteins;

0006-291X/84

five

from human plasma see 2-51.

vehicle

These

(apolipoproteins).

and characterized (for

major

apo,

EDTA, ph 8.3;

sequenced

enzymes,

density

lipo-

apolipoproteins; SSC, standard

salin

Vol. 118, No. 3, 1984 ligands

for

exchange

interaction

proteins

particles,

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS with

for

the

specific

high

transfer

and structural

affinity

of lipid

components

cellular

constituents

of lipoprotein

receptors, between

particles

lipoprotein

(for

reviews,

see 5,6).

Plasma as apoA-I, with

HDL is of major the major

shown

complete

nucleic

studies

of premature

acid

in man have

post-translational

peptidase

(16).

(20,21),

the

biosynthesis

ceptibility

of subjects

In order of apoA-I

viously

plasma

levels

which

reported Cloned

the expression

apoA-I

with

reported

DNA polymorphism

(e.g.,

analysis of the

and characterization

organization

variants

of the in

was found

A-I

region patients

and 5% in the control

hemoglobinpathies),

useful

however,

in the its

population. evaluation

potential

the

structure

type

sus-

as well We have

probes

apoA-I

as

pre-

apoA-I

Recently,

of the with

in

and metabolism

gene in normal (15).

modulate

disease.

of human liver

apolipoprotein

the 3' -flanking

which

vascular

apoA-I gene.

apoA-I

apOA-IMilano

influencing

biosynthesis of the

specific

importance

as hybridization

of the

in 44% of the

to be extremely

The factors

of premature

proapoA-I

hypertriglyceridemia,

and HDL, thereby

of the

plasma

(17-191,

mild

In

--In vivo

by an apparent

may be of major

cDNAs have been utilized

genomic

hyperlipoproteinemia,

with

as HDL.

understanding

modulate

patients

shown

our

a systematic

of the

has been

of apoA-I

the cloning

polymorphism

of apoA-I

initiated

analysis

This

as well

and the (13-15).

cell

aPOA-ITangier

to the development

to improve

we have

factors

apoA-I

reported

from the apoA-I

associated

Human apoA-I

to proapoli-I.

secretion

including

are

and processing

the

(10).

( 221,

of plasma

determining

the

of apoA-I

associated

(7-91.

has been

to mature

as well

(lo-121

cleavage

following cleavage

Variants

levels

disease

co-translational

and apOA-I#arburg

and reduced

cardiovascular

of preproapoA-I

shown that

undergoes

HDL-cholesterol

as a preproapolipoprotein

sequence

undergoes

since

of HDL, have been inversely

to be synthesized

man, preproapoA-I

importance

apolipoprotein

the development

has been

clinical

mRNA for

subjects

and

Rees et al gene

(23).

IV and type

V

DNA polymorphism of monogenic

usefulness

for

diseases

evaluation

BIOCHEMICAL

Vol. 118, No. 3, 1984 of genetic

markers

for

AND BIOPHYSICAL RESEARCH COMMUNICATIONS

hyperlipoproteinemia

and atherosclerosis

remains

to be

established. A detailed

knowledge

and expression structural

of apolipoprotein and functional

linkage

data,

to our

thirteen

apolipoproteins.

indirectly

localized

complement

C3 which

Advances specific

both

with genes

distance that

assigns

has not

resides

Olaisen

In this

analysis

have been

identified apoA-I

the apoC-III

have

direct

we assign

cell

study

which

of apoE to

genes

was less

chromosomal

to chromosome

to obtain

chromosomal

+q13

DNAs.

phage

genomic

clone

than

11 pll+ql3

in

a DNA of

(25,26).

3 Kb apart.

position

gene

usiny

Recently,

and the

on chromosome

assign-

the human apoA-I

to pll

hybrid

recombined

same region

MATERIALS

for

of apoA-I

a constant

gene to the

a family

methods

has been reported

and apoC-III

any of the

a linkage

provided

report,

in a single

of apoA-I

reported

Direct

19 (24).

localization

gene occupies assignment

present

absence

for

19 by establishing

of human-mouse

+ apoC-III

the

et al

the

gene complexes.

been reported

can be used as probes

apoA-I

our

as yet

location,

to establish

apolipoprotein

DNA technology

which

chromosomal

be required

on chromosome

11 and a regional

the apoC-III

population,

will

in the

Recently,

genes.

between

organization,

apoE to chromosome

hybridization

kindred

linkages

knowledge,

DNA sequences

to chromosome

genes

in recombinant

ment of specific

filter

of the genomic

The Assuming

the human

simultaneously 11.

AND METhODS

Apolipoprotein A-I cDNA Probe: The cDNA probe used in this study was obtained from clwibed earlier (10, 15). This clone contains the nucleic acid sequence which encodes for the entire mature apoA-I protein and A 866 base pair long cDNA insert 10 amino acid residues of the prepropeptide. was obtained by cleavage with Msp 1 [l ug DNA/2 units of enzyme for 1 hour at 37"Cl and purified by agarose gel electrophoresis (1.1%). 0.25 ug of purified DNA was radiolabeled to high specific activity (2.5 x 108 cpm/ug) by nick translation (27). Human-Mouse Somatic Cell Hybrids: Human-mouse somatic cell hybrids were constructed by fusing mouse LM/TK (thymidine kinase deficient) or RAG (hypoxanthine phosphoribosyl transferase deficient) fibroblasts with human fibroblasts or leukocytes. Proliferating cell hybrids were selected in hypoxanthine-aminopterin-thymidine medium (28). Cell hybrids were characterized for human chromosome content by trypsin-Giemsa banding (29). Filter' Hybridization: High molecular weight DNAs were isolated from human-mouse cell hybrids as previously reported (30), at the same passage as for karyotype analysis (31). Isolated DNAs (10 ug) were digested with 30 units of EcoRI 936

Vol. 118, No. 3, 1984

BIOCHEMICAL

AND BIOPHYSICALRESEARCH

COMMUNICATIONS

(Bethesda Research Laboratory) for 3 hrs at 37°C. The restriction fragments were separated by 0.7% agarose gel electrophoresis (0.8 cm x 11 cm x 14 cm) at 35 volts for 16 hours. DNA was transferred to nitrocellulose filter paper (Schleicher and Schull) for 16 hrs in TBE buffer. Hybridization was performed for 24 hrs at 42"C, and washed briefly at room temperature with 2 x SSC, 0.1% SDS, then for 30 mins at 50°C with 0.1 x SSC, 0.1% SDS as previously described (32,33). RESULTS As previously 12.5

Kb EcoRI

lane

1).

fragment

Under

was observed DNAs were the

the

with

techniques

same hybridization

from

1

a panel

technique. performed

1 illustrates for

the apoA-I

cDNA probe

of human DNA by Southern

blotting

simultaneously Figure

(15)

mouse DNA (Fig.

extracted

Southern

were

reported

cell

Filter

2

3

Therefore, cell

hybridization

on cells

lines

2).

at the

12.5 high

(Fig.

weight

and analyzed

and karotype

by

analyses

with

the apoA-I

5

6

the hybridization

gene

(lane

7

3, Xer-9;

6

12.5- -w

FIGURE

1. DNA from human diploid fibroblasts (lane 11, and mouse RAG cells lane 2) and human-mouse cell hybrids (lanes 3-8) were hybridized with a 3 1 PThe probe hybridizes to a single labelled apoA-I specific DNA fragment. 12.5 kb EcoRI human DNA fragment (indicated by the arrow), but not to mouse DliA. Cell hybrid DNAs in lanes 3-6 contain the human apoA-I gene, whereas in lanes 7 and 8 the apoA-I gene was absent. The cell hybrid DNAs in lanes 3-8 are respectively: XER-9, XER-11, XER-7; RtW-11; USL-15; EXR-5 CSAZ (See Table I for the human chromosome content of each of the hybrids).

937

1,

Kb fragment

molecular

hybrids

obtained

contained

4

(34)

same passage.

results

which

to a single

analysis

no similar

of 19 human-mouse

representative

hybrid

blotting

condition, 1, lane

hybridized

BIOCHEMICAL

Vol. 118, No. 3, 1984 lane

4, XER-11;

(lane

lane

7, NSL-15;

lane

The results shown in Table the

apoA-I

well

8, EXR-5

gene segregated

cell

the apoA-I

on chromosome

Hybridization

illustrating

11 is

shown

of an apolipoprotein

apoA-I

19 human-mouse

with

were

chromosome

performed

EXR and XER, which

gene to the

diagram

of the

11 analyses

hybrids,

(35,361.

and when the

gene was absent

CsAZl.

The apoA-I

gene on chromosome

A schematic

6, REW 11)

analysis

I.

translocations

lane

of the complete

characterized

localized

5, XER-7;

AND BIOPHYSICAL RESEARCH COMMUNICATIONS

analysis

with

pll

+ q13 region

the

regional

in Figure

This

2.

gene to a specific

To localize

chromosome

of chromosome

study

of the

permitted

are

previously

the apoA-I

assignment

lines

11.

with

contain

cell

11

cUNA probe

I).

11 (Table

apoA-I gene

a direct

assignment

chromosome.

DISCUSSION The application permitted

of recombinant

the development

of major

DNA techniques new concepts Table

Segregation

of the Apolipoprotein Human-Mouse

to human genetics of gene structure

has and organi-

1

A-l Gene with Human Chromosomes Somatic Cell Hybrids

in

Chromosomes Hybrid

1 TSL-2

-

ATR-13

-

NSL-9

-

NSL-15 JSR-17s WlL-6

+W +

2

-+ ++ -+ +-+

3

4

-++ -+ +-+

5

6

++ -+ +++++

WIL-2 WIL-14

+-

-

WIL-13 REW-11

+

XTR-22

+

WIL-7

+

WILdX

+

JWR-26C JWR-22H

+

XER-7

+

XER-9

+

XER-11

+ -

EXR-SCSAz

dmignsWd fibr&ksts fibrob!Ssts

TWV3klCSIiOll

ApoA-I

-+ -+ -+

+

++ -+ ++-

-++ --+ ++ +- ++ ++ ++ ++ ++ + -+ ++ ++ -+ -++ -+ ++ ++

7

6

-++ -+ ++ -+ ++ + -+ ---+ --+ ++-++ -+ ++ ++

9 10 11 12 13 14 15 16 17 18 19 20 21 22

X

-+ -+ -+ -++ -+ --+ ---+ -+ -+ ++ -+ ++ -+ -+ -+

+

-+ -+ -+ -+ ++ +-+ --ff+++ ++ +-+ -+ -+ -+

--+ ++ ++ ++ -+ --+ -+-+* -+ -+ -+ ++ --++

-+++ +++ -----+ ---+ ++ -+ ++ ++ ++ ++

-+ ++ +++ ++ +++++ --+ ++ ++ ++ ++ -+ ++ ++ ++

-+ --+ +-+ ++ ----+ ++ -++ -+ -+ ---+ ++

+-++ ++ ++ f+-++++ +f++-+-+ ++

hybrkh snd &-mm (mm lhe’hukm pm&al c&s usml for c&l hl&ma (20). XER hyWif& *nn oOn9trucbd cqmWinii m X;ll tran-ion: 16. X, del(11) (pllql3). t (X;ll) (qll; ~11). EXA hybrids were conStnx@d conmining a dikmnt X$1 translocation: 46. X. t (X:11) (q22; q13).

938

Chromosomes 1713 5/x

+

1719 7q-

+ + + + + + +

lP-

+

11/x

x13

2/I

11/x

+

x/11,11/x

with humm from human

GM 2SSS GM 3322

Vol. 118, No. 3, 1984

BIOCHEMICAL

AND BJOPHYSICALRESEARCH

COMMUNICATIONS

SRO pl1-D q'3

apo A-I gene

+

2. The region within the human chromosome 11 to which the apoA-I gene has been localized is shown in this schematic diagram. The normal hunan chromosome 11 is shown for reference on the left. In the center (a) is the region llpll+qter involved in the 11/X translocation segregating in the XER hybrids. On the

FIGURE

right

(b) is the region

llql3+qter

gating in EXR hybrids. or absence ("-" ) of the pll +q13.

zation

in normal

field

of lipoprotein

subjects

and physiological

virtually

nothing

protein

is

genes.

linkage

restricted

study

19 mouse-human

somatic

genetically

Since

the

apoC-III

a large

structure

cloned

11 translocations gene

has been

however, of the apolipo-

(37)

have

localized

The human

and genetic

studies

as was utilized

in establishing

as probes

permitted Further localized identified 939

presence

analysis apoA-I

sequences

assignment of cell

with

of the

hybrids

to the region

in combination

now permit

chromosome.

of apoA-I

the direct

the

19 (24).

will

of a gene to a specific of the

have

on chromosome

DNA sequences

assignment

In the on the

apolipoproteins,

locus

("+"I

(SRO) is

diseases.

and organization

of complement

11.

of overlap

genetic

et al

segre-

presence

body of information

Lusis

analysis

hybrids

the

9 and 1, respectively.

the identification cell

specific

heterogeneous

C3 component

apoA-I gene to human chromosome chromosome

the

of purified

In the present

taining

is

mouse strains,

as unequivocal

in the X/11 translocation

of the plasma

to kindred

of apoE to the

as well

there function

inbred

is

The availability direct

with

to mouse chromosome

however,

been usually

involved

each chromosome is indicated gene. The smallest region

and patients

known about

Using

and apoA-II

population,

Below apoA-I

research,

chemistry

apoA-I

+

conpll+q13.

apoA-I

in a

in

BIOCHEMICAL

Vol. 118, No. 3, 1984 single

recombinant

the pll+

q13 region

Current apoA-I the

phage

information

available within

of other

genes

homologous

of human chromosome

on mouse chromosome

proximal

to this

the

homologous recently

linked

to esterase

esterase located

17 is

identified

esterase

apoA-I

and apoC-III

on the

long

on the

and the

Human

Both

located

near 11.

resolution

--in

Thus,

to the

In the mouse,

2.

on chromosome (39).

which

would

apoA-I-esterase

the

9 (371

suggest

techniques

(40)

Genes in the Mouse

INS

Ins-l

7 7 7 7 2

Mouse Chromosome

HRASI ACPL

Acp-2

Catalase Apolipoprotein

CAT APOA-I

cs-1

2

Sep-1

9

UPS

Ups

9

ESAU

ES-1 7

9

Synthetase

Symbols reference

and (39).

chromosome

assignments

for

the

human

940

and

mouse

genes

11,

should

HBB LDHA

Esterase

group

hybrids

c-Ha-rasl Acid Phosphatase

Uroporphyrinogen

that

linkage

Mouse Gene Symbol

A-l

are

17-uroporhyrinogen

Human Gene Symbol

A

of

synthase

Hbb Ldh-1 Hras

Dehydrogenase

and

of human chromosome

of Homologous

gene

synthase

of additional

region

are

centromere;

A4 and uroporphyrinogen

hybridization

Table 2 11 Genes and the Locations

have

The human homolog

9 may have a homologous

of this

on

short-arm

and catalase

respect

Examination

Insulin @Globin Lactate

with

11 (39)

the

11.

situ

on the

A4 and uroporphyrinogen

esterase

based

of human chromogenes

phosphatase-2

synthase

esterase

genes

LDHA, and c-Ha-rasl

was located

translocations

Chromosome

Several

B-globin,

on the short-arm

of human chromosome

use of high

21.

Acid

as apoA-I,

of linked

and long-arms

(Table

on mouse chromosome

informative

group

short-

of human chromosome

are

gene can also

are on mouse chromosome

A4.

gene complex

containing

a conserved

7 (38,391.

arm of chromosome

long-arm

that

17 and uroporphyrinogen

on the long-arm

synthase

on the mouse and human gene map suggests

insulin,

of genes

mouse genes

Sep-1,

to

on the

11 including

group

be localized

mouse genes

homologs

apoC-III

the

11.

may reside

location

some 11 and the

(261,

of chromosome

+ apoC-III

known

clone

AND BIOPHYSICAL RESEARCH COMMUNICATIONS

have

been

taken

from

Vol. 118, No. 3, 1984 add additional

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS

insights

apoA-I and apoC-III

into

the structural

organization

and linkages

of the

genes. ACKNOWLEDGEMENT

We would

like

preparation

to thank of this

Ms. Barbara

Ziarnik

for

her

expert

assistance

in the

manuscript. REFERENCES

1.

Havel,

R. J.,

Eder,

H. A.,

and Bragdon,

1345-l 353. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

J. H. (1955) J. Clin.

Invest.

-’34

Jackson, R. L., Morrisett, J. D., and Gotto, A. M., Jr. (1976) Physiol. Rev. 56-, 259-316. Osborne, J. C., Jr. and Brewer, H. B., Jr. (1977) Adv. Prot. Chem. 3l-, 253-337. Scanu, A., and Teng, T. (1979) In: The Biochemistry of Atherosclerosis (A. M. Scanu, ed.), Marcel Dekker, Inc., New York and Basel, pp. 107-121. Brewer, H. B., Jr. (1981) Klin Wochenschr 2, 1023-1035. Brewer, H. B., Jr., Schaefer, E. J., Osborne, J. C., Jr., and Zech, L. A. (1979) Proceedings of the High Density Lipoprotein Methodology Workshop, Washington, DC, U.S. Govt. Printing Office, DHEW Publ. No. 79, pp. 29-42. Gordon, T., Castelli, W. P., Hjortland, M. C., Kannal, W. B., and Dawber, T. R. (1977) Am. J. Med. 62, 707-714. Castellf, W., Doyle, J. T., Gordon, T., Hames, C. G., Hjortland, M., Hulley, S. B., Kagan, A., and Zukel, W. J. (1977) Circulation 55, 767-772. Maciejko, J. J., Holmes, D. R., Kottke, B. A., Zinsmeister, A.-R., Dink, D. M., and Mao, S. J. T. (1983) N. Eng. J. Med. 309, 385-389. Law, S. W., Gray, G., and Brewer, h. B., Jr. (19m Bfochem. Biophys. Res. Commun. 112, 257-264. Gordon, J. I .,ms, H. F., Lentz, S. R., Edelstein, C., Scanu, A. M., and Straus, A. W. (1983) J. Biol. Chem. 258, 4037-4044. Zannis, V. I., Karathanasis, S. K., Keutiii%, h. T., Goldberger, G., and Breslow, J. L. (1983) Proc. Natl. Acad. Sci. USA 80, 2574-2578. Shoulders, C. C., Kornblihtt, A. R., Munro, B. S., anbBaralle, F. E. (1983) Nucl. Acid. Res. 11, 2827-2837. Cheung, P., and Chan, L.7l983) Nucl. Acid. Res. 11, 3703-3715. H. B., Jr. (1983) Proc. NXl. Acad. Sci. USA, Law, S. W., and Brewer, in press. E. J., Law, S., Light, J. A., and Brewer, H. B., Jr. Ghisellf, G., Schaefer, (1983) Clfn. Kes. 31, 500A. Kay, L. L., Ronan,-R., Schaefer, E. J., and Brewer, H. B., Jr. (1982) Proc. Natl. Acad. Sci. USA 79, 2485-2489. Schaefer, E. J ., Kay,-C. L., Zech, L. A., and Brewer, h. B., Jr. (1982) J. Clin. Invest. 70, 934-945. Brewer, H. B., Jr: Fairwell, T., Kay, L., Meng, M., Ronan, R., Law, S. W., and Light, J. A. (1983) Biochem. Biophys. Res. Commun. 113, 626-632. Weisgraber, K. H., Bersot, T. P., Mahley, R. H., Francemini, G., and Sfrtori, C. R. (1980) J. Clin. Invest. 66, 901-907. Franceschini, G., Sfrtori, C. R., Capurz, A., Weisgraber, K. H., and Mahley, R. W. (1980) J. Clin. Invest. 66, 892-900. Utermann, G., Feussner, G., FranceschiiiT, G., Haas, J., and Steinmetz, A. (1982) J. Biol. Chem. 257, 501-507. Rees, A., Shoulders, CT., Stocks, J ., Galton, D. J ., and Baralle, F.E. (19831 Lancet 1, 444-446. Olaison, O., Eisberg, P., and Gedde-Dahl, T., Jr. (1982) tium. Genet. -'62 233-236. 941

Vol. 118, No. 3, 1984 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40.

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Norum, R. A., Lakier, J. B., Goldstein, S., Angel, A., Goldberg, R. B., Block, W. D., Noffze, D. K., Dolphin, P. J., Edelgloss, J., Bogorad, D. D., and Alaupovic, P. (1982) N. Eng. 3. Med. 306, 1513-1519. Karathanasis, S. K., McPherson, J., Zannis, V. I., and Breslow, J. L. (19831 Nature 304, 371-373. Rigby, R. W. Jqieckmann, M., Rhodes, C., and Berg, P. (1977) J. Mol. Biol. 113, 237-251. Szybalm, W. S., Szybalski, E. l-l., and Raqni, G. (1962) Proc. Natl. Acad. Scil USA 7, 75-88. Seabright, M. (T971) Lancet ii, 971. Sakaguchi, A. Y., Naylor, S.-R., Shows, T. B., Tool' e, J. J., McCoy, M., and Weinberg, R. A. (1983) Science 219, 1081-1082. Shows, T. B., Sakaguchi, A. Y., andT%lor, S. L. ( 1982) Adv. Hum. Genet. 12, 341-452. %kaguchi, A. Y., Lalley, P. A., and Naylor, 5. L. (19831 Somatic Cell Genetics 2, 391-405. Naylor, S. L., Sakaguchi, A. Y., Shen, L-P., Bell, G. I., Rutter, W. J., and Shows, T. B. (19831 Proc. Natl. Acad. Sci. USA 80, 2686-2689. Southern, E. M. (1975) J. Mol. Biol. 98, 503-517. Owerbach, D., Rutter, W. J., Shows, ‘IT;-B., Gray, P., Goeddel, D. V., Lawn, R. M. (19811 Proc. Natl. Acad. Sci. USA 78, 3123-3127. Lebo, R. V., Kan, Y. W., Cheung, M. C., CarranK A. V., Yu, L. C., Chang, 3. C., Cordell, B., and Goodman, H. M. (1982) Human Genet. 60, 10-15. Lusis, A. J ., Taylor, B. A., Wangenstein, R. W., and LeBoeuf, R. CF(19831 J. Biol. Ghem. 258, 5071-5078. Sakaguchi, A. Y?alley, P. A., Zabel, 8. U., Ellis, R., Scolnick, E., and Naylor, S. L. (1983) Proc. Natl. Acad. Sci. USA, in press. Human Gene Mapping Workshop VII (1983) Cytogenet. Cell Genet., in press. label, 8. U., Naylor, S. L., Sakaguchi, A. Y., and Shows, T. B. (1983) Proc. Natl. Acad. Sci. USA, in press.

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