Pituitary Luteinizing Hormone and Prolactin Messenger Ribonucleic ...

OF

BIOLOGY

47, 598-602

REPRODUCTION

Pituitary

Luteinizing Inversely ERIC

JANET

of Animal

Department Department

and Prolactin

Related

A. WONG,2’3

Department

(1992)

Hormone

in Laying

L. SILSBY,4

Science,3

of Animal

of Biology,5

Ribonucleic

and Incubating

SUSUMU

Virginia

ISHII,5

and

Turkey

University

and

of Minnesota,

of Education,

Waseda

Levels

Are

E. EL HALAWANI4

State

University,

St. Paul,

University,

Acid

Hens1

MOHAMED

Polytechnic Institute Virginia 24061

Science,4

School

Messenger

Blackthurg

Minnesota

Shinjuku-ku,

55108 Tokyo

160,

Japan

ABSTRACT The hens

relationships

at different content

PRL

6-fold,

phase.

not

did

of UI-K

In the

mRNA

were

low.

levels

and

hens.

as dramatically.

PRL

and

shows

three PRL

to PRL

levels,

to its lowest in incubating

that

Factors

seem

gonadotropic there and

PRL

to of

function, a number

In

unknown.

states,

tend

capable

increase

prolactin

suppressing

control

Secretion

relationship

between

of

bating

of PRL in the reviewed by

the

tion

of

and

PRL

gonadotropins

lactation

hyperprolactinemia UI

levels

verse

related

minished [10, 11],

secretions

From

PRL

levels

a number

[15], and

and

of

physi-

[7], turkeys [13], ring spotted

depressed

in-

13 mRNA

is asso-

levels

PRL

and

hens

barely

detectable

Animal

of incu-

Accepted

by USDA

grants

#88-37242-03845

Dr. Eric A. Wong, Department

2Correspondence: Institute

and

State

University,

Blacksburg,

of Animal

Science,

VA 24061-0306.

Virginia

FAX:

(703)

Turkey

periments. The nonphotostimulated, photorefractory were maintained

and

91-37203-6609. technic

exogenous

PRL suppresses

secretion

that

chickens

occurs are

after deprived

between plasma PRL and relationship may exist

UI

the

corre-

levels of pituitary [H 13-subunit (m) RNA with pituitary and

serum

the

genes.

To

determine

UI for

of turkey

pituitaries

(UI-

hens

at dif-

cycle were analyzed hens maintained high

and low PRL mRNA dramatically elevated UI-13 mRNA levels.

levels, whereas PRL mRNA levels

on UI-

incuand

Poly231-

6L:18D

3010.

598

AND

METHODS

Studies

Hatchmate

in part

[22]. of PRL levels results in corUI. The injection of PRL antiincrease in UI levels in incu-

incubating

MATERIALS

cholas June 11, 1992. Received January 17, 1992. tThese studies were supported

deprivation [17-20], the pharmacological

di-

[16].

levels

and

from

had

mRNA Pituitary

hens.

by nest [211, or

in UI

or when

levels

bating

3-, and

-subunlt

turkey

[20]. relationship a comparable

[8,9], ducks doves [14],

sandpipers UI

incubating

[23]. Furthermore,

RNA

in-

80-,

mRNA abundance was highest results demonstrate that the abun-

phases of the reproductive Northern blots. Photostimulated

secretion activity

total

the

57-fold

phases.

ferent

an

gonadotropin

of incubation circulating

levels,

during

UI-B

lation of the steady-state 13) and PRL messenger

controlled

conditions,

PRL and

The onset enhanced

are

UI

pituitary

synthesis

of PRL

and

declined

reproductive

increase

nests inverse that

peaked 11-,

levels

be reversed of chicks

[24]

expression

by diminished

reproductive

between

sparrows

elevated

inappro-

[4-6].

UI levels in bantam hens canaries [12], wild starlings

white-crowned

of

chickens

observed

of their The suggests

experimental

is accompanied

gonadotropin

experimental

to emerge. with greatly

stages

Additionally,

mechanisms.

relationship

seems ciated

The

sexes

PRL and

or

ological

[3].

in rats

in both

In birds, by closely

during

in women

and

of serotonin

ovariectomy

McNeilly [1]. During postpartum lactation in rats, serum PRL is high whereas serum UI and FSH are relatively low [2]. A similar relationship appears to exist between the secrepriate

peak

different

and

and

for turkey and pituitary

serum

220-,

Experimental manipulation responding changes in serum serum is associated with an

is

secretion

The role has been

LII,

the

hens. Pituitary hens. These

blockade

although the precise mechanism of reproductive and pathological

is an inverse

pituitary for

bating hens can the introduction

hypothalamic-pituitary

secretion of gonadotropins. of gonadotropin secretion

UI,

changes

determined

hen,

showed

These

in photostimulated/laying

relationship

(PRL)

hens

respectively.

serum

were

inactive

photostimulation

incubating

level in incubating and photorefractory

INTRODUCTION

also

after

rose

levels,

mRNA

content

reproductively

values

no significant

showed

an inverse

PRL

pituitary

and

hyperprolactinemic

pituitary

LII

and declined hens and lowest

mRNA

All

In contrast

Serum

to serum

RNA

nonphotostimulated,

hens,

content,

PRL

photostlmulation and laying

(m)

messenger

UI

cycle.

in photorefractory

change

LU peaked after In photostimulated dance

and

reproductive

to nonphotostimulated

pituitary

PRL,

respectively,

levels

PRL

Relative

in serum

(PRL)

of the

pituitary

and

Incubation creases

of prolactin phases

turkeys

of the

Farms,

Sonoma,

large

white

CA) were

female used

line

reproductive groups used in this study photostimulated, laying, incubating, hens. Quiescent or nonphotostimulated under a nonstimulatory photoregimen

for at least

8 wk.

These

birds

possessed

(Ni-

for these

exwere and hens of

a regressed

AND

LII

ovary

and

oviduct

and

to a stimulatory switched from

would

hens

the

and six

nest

or

reproductive

aggressive nest protection were allowed to progress to

where

and

migration

LH-13,

on

were

stripped

and

from

and

citrate,

from

ladder

and

pH

A. LH mRNA NPS PS 12345678

L

PR 910

‘-0.9kb B. PRL mRNA ‘-3.1kb

laying

7.0;

with

and

Turkey

at

pituitar-

turkey

gels containing were based on kb; to

1.0%

Gene action

Columbia,

normalized LH-13 and

and chicken as described prefirst with chicken PRL,

and

finally

to

LH-13

and

to 13-actin mRNA levels PRL by the ADU for [3-actin

or six different were analyzed,

‘-2.0kb

PRL,

corresponding

MD).

mRNA

Screen and hy-

SDS.

(ADUs)

C. 6-actin

GIBCO-BRL,

for LH-13, PRL, and 13-actin mRNA by densitometry (Shimadzu CS 90004

Shimadzu,

as mean

hens in liquid

isothiocyanate RNA were loaded

(0.24-9.5

units

determined

levels were ADU5 for

turkey

with chicken 13-actin. Membranes for 30 mm in 0.015 M NaCl; 0.0015

of hybridization

each sample. Five ductive condition

samples for each and the results

FIG. 1. Northern blot of pituitary LH, prolactin, and -actin mRNA abundance. Total RNA was extracted from individual pituitaries of turkey hens at different stages of the reproductive cycle. Two replicate hens from each reproductive phase are shown: nonphotostimulated (NPS). lanes 1 and 2; photostimulated (PS). lanes 3 and 4; laying (L), lanes 5 and 6; incubating (I), lanes 7 and 8; and photorefractory (PR), lanes 9 and 10. A) The blot was probed with a radiolabeled chicken LH cDNA. Exposure time was 2 days. B) The blot was stripped and reprobed with turkey PAL eDNA. Exposure time was 16 h. C) The blot was again stripped and reprobed with chicken -actin cDNA. Exposure time was 2 days.

PRL

by for

reproare re-

Institute,

Cary,

identifIed cances

NC).

by use were

Significantly

of Duncan’s

reported

at p